53 results on '"Silvia Carbone"'
Search Results
2. Ações e Implicação para a (Ex)Inclusão 2
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Jôsi Mylena de Brito Pinheiro, Edivaldo Lubavem Pereira, Franklin Portela Correia, Kátia de Abreu Fonseca, Denise de Almeida, Larissa Gonçalves Moraes, Silvia Cristina Pereira dos Santos, Klalter Bez Fontana, Marcelo Marques de Araujo, Lívia Mello Lopes de Almeida, Caroline Boaventura Czelusniak, Renata Souza Vogas, Camila Elidia Messias dos Santos, Isadora Polvani Barbosa, Waleska Souto Maia, João Carlos dos Santos Duarte, Natália Cristina de Almeida Azevedo, Jose Alexandre de Lucca, Elisabeth Rossetto, Bianca de Oliveira, Patricia Siqueira Dos Santos, Cláudia Terra do Nascimento Paz, Odinilton Pacheco De Deus, Cláudia Medianeira Alves Ziegler, Marcio Roberto Ghizzo, Luecy Verônica Mendes Garcia David, Silvia Raquel Schreiber Boniati, Mequias Pereira De Oliveira, Silvia Carbone, Vânia Silva de Melo, Erica Silvani Souza, Natália Schleder Rigo, Cintia Soares Romeu, Elizabeth Cardoso Gerhardt Manfredo, Cilene Angelica Peres, Ivan de Oliveira Silva, Solange de Castro, Maria Beatriz Campos de Lara Barbosa Marins Peixoto, Luana Tillmann, Sonia Ribeiro de Lima, Isabel Rodrigues Monteiro, Erika da Silva Chagas, Érica Caléfi, Marco Antonio Serra Viegas, Robson Paz Vieira, Raquel Amorim Dos Santos, Fabiane Araujo Chaves, Roger Alloir Alberti, Isabel Lopes Valente, Judith Mara de Souza Almeida, Jair Lopes Junior, Eleny Brandão Cavalcante, Alexandre Vanzuita, Simone De Mamman Ferreira, Thacio Azevedo Ladeira, Idorlene da Silva Hoepers, Lidnei Ventura, Vera Lucia Messias Fialho Capellini, Geilsa Soraia Cavalcanti Valente, Mariana Roque Lins da Silva, and Eduardo Gonzaga Bett
- Published
- 2020
3. L'assistente sociale in psichiatria. Riflessioni ai margini di una professione
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Silvia Carbone
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Health (social science) ,Social work ,business.industry ,Health Policy ,media_common.quotation_subject ,social work-social worker-social health- integration-mental health services ,Public relations ,Mental health ,Negotiation ,Close relationship ,Mental health care ,Position (finance) ,Sociology ,business ,Professional group ,Autonomy ,media_common - Abstract
The research is a study of two cases and have been used 15 in-depth interviews made to the social workers of different mental health services in Messina and Agrigento. Research is moving along a path of inductive and exploratory. It has tried understanding the characteristics of the social worker’s job. They were examined by public psychiatric services of the Departments of Mental Health of Messina and Agrigento. The aim of this paper is to reflect on the close relationship between social workers and other professionals in the mental health care of public facilities, such as psychiatrists. The intention is to respond to the need to examine the interaction of this professional group and better understand the different path by which you can keep autonomy and/or negotiate professional position, especially in relation to other professions medical sector. We have chosen to focus on the social worker’s role in psychiatry because it is the key figure of the present socio-health integration process. This has given rise to numerous challenges related to building and strengthening its social identity-professional.
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- 2018
4. La productividad territorial y el rol de la cartografía en la defensa del parque Reforma Social, Ciudad de México
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Silvia Carbone and Stéphane Couturier
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Capital investment ,Coronavirus disease 2019 (COVID-19) ,media_common.quotation_subject ,Geography, Planning and Development ,Power relations ,Real estate ,Urban Studies ,Appropriation ,Promotion (rank) ,Economy ,Mexico city ,Political science ,Economic model ,Nature and Landscape Conservation ,media_common - Abstract
El impulso del modelo económico neoliberal en la Ciudad de México ha estimulado la inversión de capital en obras e intervenciones, las cuales desencadenan problemas entre los actores sociales involucrados. El siguiente artículo propone un análisis del conflicto en torno al carácter público del parque Reforma Social, ubicado en la alcaldía Miguel Hidalgo, en el que asistimos al enfrentamiento de intereses entre los vecinos —movilizados para conservar el parque— y un grupo de actores que tiene planeado desarrollar un proyecto inmobiliario. En el marco de las pugnas territoriales que atraviesan esta metrópolis, analizamos la controversia bajo el supuesto de que esta modifica las relaciones de poder previas al estallido de la confrontación y tiene una productividad. Después de delimitar el conflicto como situación, se recupera la voz de los actores, sus argumentos y posicionamientos, desde una lectura que analiza las alianzas, así como la capacidad de los vecinos de proponer nuevas estrategias de defensa territorial. Dentro de los resultados, se evidencia cómo al mismo tiempo que se incrementa la cohesión de los residentes, se reconoce el papel protagónico desempeñado por la cartografía, en particular, en lo que concierne al proceso de apropiación y de proyección territorial experimentado por los vecinos de la colonia.
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- 2021
5. Influence of third-body particles originating from bone void fillers on the wear of ultra-high-molecular-weight polyethylene
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Sean S. Aiken, Silvia Carbone, L M Jennings, Raelene M. Cowie, and John J. Cooper
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Reoperation ,wear ,Third body ,Materials science ,Surface Properties ,Joint Prosthesis ,0206 medical engineering ,third-body damage ,Biocompatible Materials ,02 engineering and technology ,calcium sulfate ,03 medical and health sciences ,chemistry.chemical_compound ,Reciprocating motion ,0302 clinical medicine ,Materials Testing ,Humans ,ultra-high-molecular-weight polyethylene ,Composite material ,Ultra-high-molecular-weight polyethylene ,030222 orthopedics ,Mechanical Engineering ,Chromium Alloys ,Bone Cements ,in vitro ,Cobalt-chrome ,Original Articles ,General Medicine ,Polyethylene ,Bone cement ,020601 biomedical engineering ,Biomechanical Phenomena ,Prosthesis Failure ,Knee replacement ,chemistry ,bone void filler ,Bone Substitutes ,Void (composites) ,Polyethylenes - Abstract
Calcium sulfate bone void fillers are increasingly being used for dead space management in infected arthroplasty revision surgery. The presence of these materials as loose beads close to the bearing surfaces of joint replacements gives the potential for them to enter the joint becoming trapped between the articulating surfaces; the resulting damage to cobalt chrome counterfaces and the subsequent wear of ultra-high-molecular-weight polyethylene is unknown. In this study, third-body damage to cobalt chrome counterfaces was simulated using particles of the calcium sulfate bone void fillers Stimulan®(Biocomposites Ltd., Keele, UK) and Osteoset®(Wright Medical Technology, TN, USA) using a bespoke rig. Scratches on the cobalt chrome plates were quantified in terms of their density and mean lip height, and the damage caused by the bone void fillers was compared to that caused by particles of SmartSet GMV PMMA bone cement (DePuy Synthes, IN, USA). The surface damage from Stimulan®was below the resolution of the analysis technique used; SmartSet GMV caused 0.19 scratches/mm with a mean lip height of 0.03 µm; Osteoset®led to a significantly higher number (1.62 scratches/mm) of scratches with a higher mean lip height (0.04 µm). Wear tests of ultra-high-molecular-weight polyethylene were carried out in a six-station multi-axial pin on plate reciprocating rig against the damaged plates and compared to negative (highly polished) and positive control plates damaged with a diamond stylus (2 µm lip height). The wear of ultra-high-molecular-weight polyethylene was shown to be similar against the negative control plates and those damaged with third-body particles; there was a significantly higher ( p
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- 2016
6. Stranieri cinesi e accesso ai servizi sanitari. I risultati di uno studio a Messina
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Silvia Carbone
- Abstract
Il diritto alla salute fa parte dei diritti universalmente riconosciuti e garantiti ad ogni individuo, indipendentemente dal possedimento o meno dello status di cittadino. Avere accesso alle cure quando e necessario e un modo per gli stranieri di far valere questo diritto e di mantenere il loro stato di salute. Dagli ultimi dati Istat e del Ministero della Salute risulta che la popolazione straniera cinese si caratterizza per un tasso di ospedalizzazione significativamente piu basso rispetto ad altre comunita di stranieri. Questa ricerca si concentra sull’analisi della modalita di accesso ai servizi sanitari da parte della popolazione cinese di Messina. Le caratteristiche della comunita di indagine, hanno portato a privilegiare strumenti di analisi di tipo quantitativo. Sono stati somministrati 130 questionari a risposta chiusa. I primi risultati che emergono dalla ricerca sono: l’orientamento diffuso tra i cinesi di fare un uso differenziato della medicina tradizionale e di quella occidentale; il diffidare dei servizi sanitari locali perche costretti ad affrontare diversi ostacoli linguistici e logistici.
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- 2016
7. Wear of composite ceramics in mixed-material combinations in total hip replacement under adverse edge loading conditions
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John Fisher, Mazen Al-Hajjar, Daniel Delfosse, Silvia Carbone, Sabine Begand, Louise M. Jennings, and Thomas Oberbach
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030222 orthopedics ,Materials science ,Bearing (mechanical) ,Zirconia Toughened Alumina ,Metallurgy ,Composite number ,Biomedical Engineering ,Total hip replacement ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Edge loading ,Hip replacement (animal) ,law.invention ,Biomaterials ,03 medical and health sciences ,0302 clinical medicine ,law ,visual_art ,visual_art.visual_art_medium ,Cubic zirconia ,Ceramic ,0210 nano-technology - Abstract
Ceramic composites have performed very well under adverse edge loading conditions when used in like-on-like configurations, where the femoral head and acetabular cup are of the same material. The aim of this study was to determine the wear of pure alumina (Al2 O3 ), alumina toughened zirconia (ATZ) and zirconia toughened alumina (ZTA) when used in mixed bearing combinations, under edge loading conditions due to translational mal-positioning. The head-on-cup configurations of three ceramic materials were ATZ-on-ZTA, ZTA-on-ATZ, Al2 O3 -on-ATZ, ATZ-on-Al2 O3 , Al2 O3 -on-ZTA, and ZTA-on-Al2 O3 . They were tested on the Leeds II hip simulator under microseparation conditions. The bedding in and steady state wear rates of ATZ-on-ZTA were 1.16mm3 /million cycles and 0.18mm3 /million, respectively, and for ATZ-on-Al2 O3 were 0.66 mm3 /million cycles and 0.20 mm3 /million, respectively. The wear rates of the other bearing combinations under these adverse microseparation conditions, Al2 O3 -on-ATZ, Al2 O3 -on-ZTA, ZTA-on-ATZ and ZTA-on-Al2 O3 were very low with no clear bedding in and steady state phases, and with steady state wear rates lower than 0.11 mm3 /million. The mixed material combinations tested in this study have shown slightly higher wear rates when compared to ATZ in like-on-like configuration reported previously, but superior wear resistance when compared to alumina-on-alumina bearings tested previously under the same adverse microseparation conditions. © 2016 The Authors Journal of Biomedical Materials Research Part B: Applied Biomaterials Published by Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1361-1368, 2017.
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- 2016
8. Influence of conformity on the wear of total knee replacement: An experimental study
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Claire L, Brockett, Silvia, Carbone, John, Fisher, and Louise M, Jennings
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Total knee replacement ,polyethylene ,wear ,Original Articles ,Arthroplasty, Replacement, Knee ,Prosthesis Design ,human activities ,Mechanical Phenomena ,Prosthesis Failure ,conformity - Abstract
Wear of total knee replacement continues to be a significant factor influencing the clinical longevity of implants. Historically, failure due to delamination and fatigue directed design towards more conforming inserts to reduce contact stress. As new generations of more oxidatively stable polyethylene have been developed, more flexibility in bearing design has been introduced. The aim of this study was to investigate the effect of insert conformity on the wear performance of a fixed bearing total knee replacement through experimental simulation. Two geometries of insert were studied under standard gait conditions. There was a significant reduction in wear with reducing implant conformity. This study has demonstrated that bearing conformity has a significant impact on the wear performance of a fixed bearing total knee replacement, providing opportunities to improve clinical performance through enhanced material and design selection.
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- 2017
9. Exposure to a low dose of bisphenol A impairs pituitary-ovarian axis in prepubertal rats
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P. Scacchi Bernasconi, Nancy Patricia Cardoso, Silvia Carbone, Romina Penalba, Osvaldo J. Ponzo, P. Scacchi, Roxana Reynoso, Juan Manuel Gámez, and Matías Pandolfi
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Pharmacology ,endocrine system ,medicine.medical_specialty ,Bisphenol A ,Offspring ,Health, Toxicology and Mutagenesis ,Low dose ,Day of life ,Relative weight ,General Medicine ,Biology ,Toxicology ,Ovarian weight ,chemistry.chemical_compound ,Endocrinology ,chemistry ,Internal medicine ,medicine ,Folliculogenesis ,Antrum ,hormones, hormone substitutes, and hormone antagonists - Abstract
The research work studies the effect of providing a low dose of bisphenol A (BPA), on the reproductive axis of prepubertal female rats. Wistar mated rats were treated with either 0.1% ethanol or BPA in their drinking water until their offspring were weaned on the 21 day of birth. The estimated average dose of exposure to dams was approximately 3 μg/kg/day. The pups were sacrificed at the 30th day of life. Body weight at the moment of the sacrifice was significantly higher in the group exposed to BPA; ovarian weight and its relative weight were not modified. LH and estradiol levels increased significantly, meanwhile FSH ones showed no significant changes. The number of primary, secondary and atretic follicles increased and antral ones was decreased. Our results demonstrated that early exposure to a low dose of BPA disrupts the normal function of the reproductive axis in prepubertal female rats.
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- 2015
10. Behavioral effects of the combined use of alcohol and energy drinks on alcohol hangover in an experimental mice model
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Silvia Carbone, Rodolfo A. Cutrera, Lucas Gustavo Asorey, and Bárbara J. Gonzalez
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Male ,Elevated plus maze ,CIENCIAS MÉDICAS Y DE LA SALUD ,Neurociencias ,030508 substance abuse ,ALCOHOL ,Alcohol ,Motor Activity ,ANXIETY-LIKE BEHAVIOR ,Physical strength ,Open field ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,LOCOMOTOR ACTIVITY ,0302 clinical medicine ,Alcohol hangover ,ALCOHOL HANGOVER ,medicine ,Animals ,Energy Drinks ,ENERGY DRINKS ,Ethanol ,Behavior, Animal ,business.industry ,General Neuroscience ,Motor coordination ,MICE ,Medicina Básica ,chemistry ,Anesthesia ,Models, Animal ,NEUROMUSCULAR COORDINATION ,Anxiety ,Blood Alcohol Content ,medicine.symptom ,0305 other medical science ,business ,Alcoholic Intoxication ,030217 neurology & neurosurgery - Abstract
In last few years it has been a significant increase in the consumption of alcohol combined with energy drink. The aim of this work was to study the effect of this mixture in motor and affective behaviors during an alcohol hangover episode. Male Swiss mice received one of the following treatments: saline + sucrose; saline + energy drink; ethanol + sucrose; ethanol + energy drink. Ethanol dose was 3.8 g/kg BW (i.p.) and energy drink dose was 18 ml/kg BW (gavage) at ZT1 (8 am) (ZT: Zeitgeber time; ZT0: 7 am; lights on). The behavioral tests used were tight rope test to determine motor coordination; hanging wire test to study muscular strength; elevated plus maze and open field tests to evaluate anxiety like-behavior and locomotor activity. Tests were carried out at basal point that matched with lights onset and every 6 h up to 18 h after treatments. Hangover onset was established at ZT7 when blood alcohol concentration (BAC) was almost zero. Our results showed that the mixture of alcohol and energy drink altered significantly motor skills. Specifically, a significant decrease was observed in the performance of the animals in the tightrope and hanging wire tests in groups treated with the mixture of alcohol and energy drink. A significant impairment in the anxiety-like behavior was observed mainly at the beginning of alcohol hangover. These findings suggest that energy drink added to alcohol extends motor disabilities observed during an alcohol hangover episode in comparison with animals that received alcohol alone. Fil: Asorey, Lucas Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; Argentina Fil: Carbone, Silvia Elena. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina Fil: Gonzalez, Bárbara J.. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas; Argentina Fil: Cutrera, Rodolfo Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; Argentina
- Published
- 2017
11. PEEK and CFR-PEEK as alternative bearing materials to UHMWPE in a fixed bearing total knee replacement: An experimental wear study
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Claire L, Brockett, Silvia, Carbone, John, Fisher, and Louise M, Jennings
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Knee replacement ,PEEK ,CFR-PEEK ,Wear ,human activities ,Article - Abstract
New bearing materials for total joint replacement have been explored as the need to improve longevity and enhance performance is driven by the changing demands of the patient demographic. Carbon-reinforced PEEK has demonstrated good wear characteristics in experimental wear simulation in both simple geometry pin-on-plate studies and in total hip joint replacement. Carbon reinforced PEEK CFR-PEEK has the potential to reduce tibial insert thickness and preserve bone in the knee. This study investigated the wear performance of PEEK and CFR-PEEK in a low conformity total knee replacement configuration. Custom-made flat inserts were tested against cobalt-chromium femoral bearings in a knee wear simulation for a period of three million cycles. Wear was assessed gravimetrically at intervals throughout the study. The wear rates of both PEEK and CFR-PEEK were very high and almost two orders of magnitude higher than the wear rate of UHMWPE under comparable conditions. Evidence of mechanical failure of the materials, including surface cracking and delamination was observed in both materials. This study highlights that these materials may not be suitable alternatives for UHMWPE in low-conformity designs., Highlights • Study investigated wear of PEEK and CFR-PEEK as alternative to PE in TKR. • Very high wear rates observed for both PEEK and CFR-PEEK. • Wear rates two orders of magnitude higher than UHWMPE under same conditions. • Evidence of mechanical failure of PEEK and CFR-PEEK materials.
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- 2017
12. L'incontro tra familiari e operatori dei servizi psichiatrici. Verso una decostruzione della colpa
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Silvia Carbone
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General Earth and Planetary Sciences ,General Environmental Science - Abstract
Nell’ultimo decennio, l’aumento delle modalita di contatto tra due entita, servizi psichiatrici e familiari, indispensabili entrambe per sostene- re il percorso di riabilitazione individuale del soggetto, ha modificato le richieste e conseguentemente le aspettative, ma ha anche fatto emergere nuove difficolta e conflitti. Puo il moltiplicarsi delle occasioni di contatto, tra operatori e familiari, favorire il sorgere di atteggiamenti di colpevolizzazione da parte degli operatori stessi nei confronti della famiglia, sulla base dell’influenza di quegli orientamenti teorici sistemico-relazionali dell’inizio del XX secolo che riconoscevano nei familiari il loro essere concausa della sofferenza del proprio caro? E come incide tutto cio sulla collaborazione? Questa ricerca e stata condotta presso alcune strutture pubbliche di Roma. La caratteristica del contesto relazionale ha portato a privilegiare come strumenti di analisi le interviste qualitative. Sono state raccolte ventisei interviste.
- Published
- 2014
13. Reproductive axis response to repeated lipopolysaccharide administration in peripubertal female rats
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Jaime A. Moguilevsky, Roxana Reynoso, Pablo Arias, Silvia Carbone, Nancy Patricia Cardoso, Osvaldo J. Ponzo, Pablo Scacchi, and Berta Szwarcfarb
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Lipopolysaccharides ,medicine.medical_specialty ,Lipopolysaccharide ,Physiology ,medicine.medical_treatment ,Glutamic Acid ,Biology ,Biochemistry ,Gonadotropin-Releasing Hormone ,Butyric acid ,chemistry.chemical_compound ,Immune system ,Internal medicine ,medicine ,Animals ,Sexual Maturation ,Rats, Wistar ,gamma-Aminobutyric Acid ,Reproduction ,General Medicine ,Glutamic acid ,Rats ,Cytokine ,Endocrinology ,chemistry ,Hypothalamus ,Female ,Luteinizing hormone ,Hormone - Abstract
Immune system disorders are often accompanied by alterations in the reproductive axis. Several reports have shown that administration of bacterial lipopolysaccharide (LPS) has central inflammatory effects and activates cytokine release in the hypothalamus where the luteinizing hormone releasing hormone (Gn-RH) neurons are located. The present study was designed to investigate the effect of repeated LPS administration on the neuroendocrine mechanisms of control of the reproductive axis in peripubertal female rats (30-day-old rats). With this aim, LPS (50 μg/kg weight) was administered to the animals during 25, 27 and 29 days of age and sacrificed on 30 day of life. Gn-RH, γ−amino butyric acid (GABA) and glutamic acid (GLU), two amino acids involved in the regulation of Gn-RH secretion, hypothalamic content were measured. LH and estradiol serum levels were also determined and the day of vaginal opening examined. The results showed a significant increase in Gn-RH and GLU content (p < 0.0001), shared by a reduction of GABA one (p < 0.0001). LH and estradiol serum levels were decreased (p < 0.01, p < 0.001) and delay in the day of vaginal opening was also observed in treated animals. Present results show that repeated LPS administration impaired reproductive function, modifying the neuroendocrine mechanisms of control of the axis in peripubertal female rats.
- Published
- 2010
14. Impact of 4-Methylbenzylidene-camphor (4-MBC) during Embryonic and Fetal Development in the Neuroendocrine Regulation of Testicular Axis in Prepubertal and Peripubertal Male Rats
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Silvia Carbone, Osvaldo J. Ponzo, Roxana Reynoso, M.L. Deguiz, Berta Szwarcfarb, Jaime A. Moguilevsky, Pablo Scacchi, and M.E. Carou
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Male ,Hypothalamo-Hypophyseal System ,endocrine system ,medicine.medical_specialty ,medicine.drug_class ,Endocrinology, Diabetes and Metabolism ,Hypothalamus ,Glutamic Acid ,Biology ,Gonadotropin-Releasing Hormone ,Follicle-stimulating hormone ,Endocrinology ,Fetal Stage ,Pregnancy ,Internal medicine ,Testis ,Internal Medicine ,medicine ,Animals ,Endocrine system ,Rats, Wistar ,Chromatography, High Pressure Liquid ,gamma-Aminobutyric Acid ,Analysis of Variance ,Aspartic Acid ,Fetus ,Dose-Response Relationship, Drug ,Organ Size ,General Medicine ,Luteinizing Hormone ,Camphor ,Prolactin ,Rats ,Prenatal Exposure Delayed Effects ,Prepubertal stage ,Female ,Follicle Stimulating Hormone ,Gonadotropin ,Luteinizing hormone ,Sunscreening Agents - Abstract
4-Methylbenzylidene-camphor (4-MBC), an UV-B ray filter, belongs to the endocrine disrupters involved with alterations in the reproductive axis. Our target was to study the effect of 4-MBC on the neuroendocrine parameters that regulate reproduction in prepubertal and peripubertal male rats, which received this disrupter during embryonic and fetal development. 4-MBC was administered (sc) to female rats since pregnancy onset in doses of 20, 100 and 500 mg/kg/day. The litters were sacrificed at 15 or 30 days old to determine testicular weight, gonadotropin and prolactin serum levels and also GnRH and amino acids release from the hypothalamus. The exposure to 20 mg/kg/day only increased the LH serum levels in 30-day-old males. Doses of 100 and 500 mg/kg/day caused a decrease in testicular weight and in LH, GnRH and glutamate levels, in prepubertal rats (15-day-old specimens), and an increase in, gonadotropin (LH and FSH) con-centration and aspartate levels in peripubertal rats (30-day-old specimens), without changes in testicular weight. Prolactinaemia remained unaltered in all groups. Results obtained show that the administration of high doses of 4-MBC during embryonic and fetal stage inhibits the testicular axis in male rats during the prepubertal stage and stimulates it during peripubertad stage. On the other hand in the case of low doses no significant effects were observed.
- Published
- 2009
15. Octyl-Methoxycinnamate (OMC), an Ultraviolet (UV) Filter, Alters LHRH and Amino Acid Neurotransmitters Release from Hypothalamus of Immature Rats
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Silvia Carbone, Roxana Reynoso, Jaime A. Moguilevsky, G. Bollero, Osvaldo J. Ponzo, B. Szwarcfarb, and Pablo Scacchi
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Male ,medicine.medical_specialty ,Ultraviolet Rays ,Excitatory Amino Acids ,Endocrinology, Diabetes and Metabolism ,Drug Evaluation, Preclinical ,Hypothalamus ,Biology ,Inhibitory postsynaptic potential ,Gonadotropin-Releasing Hormone ,chemistry.chemical_compound ,Endocrinology ,Internal medicine ,Internal Medicine ,medicine ,Animals ,Sexual Maturation ,Rats, Wistar ,Neurotransmitter ,gamma-Aminobutyric Acid ,chemistry.chemical_classification ,Neurotransmitter Agents ,Sex Characteristics ,Glutamate receptor ,Octyl methoxycinnamate ,General Medicine ,Rats ,Amino acid ,chemistry ,Cinnamates ,Amino acid neurotransmitter ,Excitatory postsynaptic potential ,Female ,Sunscreening Agents - Abstract
OMC (octyl-methoxycinnamate), is an endocrine disruptor with estrogenic activity, which is used in sunscreen creams as a UV filter. We studied its " IN VITRO" effects on the hypothalamic release of LHRH as well as on the amino acid neurotransmitter system in immature rats of 15 (prepubertal) and 30 (peripubertal) days of age. OMC decreased the LH-RH release significantly in male and female rats of both age. In male rats OMC increased the release of GABA while in the female ones It diminished the excitatory amino acid aspartate (ASP) and Glutamate (GLU) without modifications in the hypothalamic GABA release. These results suggest that during sexual maturation the inhibitory effect of OMC on LH-RH release appears to be related to its action on the inhibitory and excitatory amino acid neurotransmitters in male and female rats.
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- 2008
16. Effect of Bacterial Lipopolysaccharide on the Reproductive Axis of Prepubertal and Peripubertal Female Rats
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Silvia Carbone, Pablo Scacchi, Nancy Patricia Cardoso, Roxana Reynoso, Jaime A. Moguilevsky, Osvaldo J. Ponzo, and Berta Szwarcfarb
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medicine.medical_specialty ,Lipopolysaccharide ,biology ,Endocrine and Autonomic Systems ,Leptin ,Immunology ,Glutamate receptor ,Adipose tissue ,Proinflammatory cytokine ,Nitric oxide synthase ,chemistry.chemical_compound ,Endocrinology ,Immune system ,Neurology ,chemistry ,Internal medicine ,medicine ,biology.protein ,Hormone - Abstract
The immune, endocrine and nervous systems are closely interrelated, which allows the organism to respond to different types of stress such as infection. Chronic infectious and inflammatory conditions are often accompanied by an impaired reproductive function. Leptin, a hormone produced by adipose tissue, exerts a regulatory function on the reproductive axis. It has homology with other proinflammatory cytokines and could be modified by lipopolysaccharide (LPS). Therefore, these studies were designed to investigate the effect of LPS administration on the neuroendocrine mechanisms involved in the regulation of the reproductive axis during sexual maturation. Fifteen- and 30-day-old female rats were injected with a single dose of LPS 250 µg/kg (i.p.) and then nitric oxide synthase (NOS) activity, hypothalamic excitatory/inhibitory amino acids and Gn-RH content, serum LH and leptin concentration were studied. In 15-day-old female rats LPS treatment did not modify hypothalamic inducible (iNOS) and constitutive (cNOS) NOS activity, Gn-RH, glutamate (GLU) and GABA content. Also serum LH and leptin levels were not modified. In 30-day-old rats LPS increased iNOS and cNOS activity (p < 0.001) and hypothalamic Gn-RH content (p < 0.001). At this age hypothalamic GABA content was significantly decreased (p < 0.001) without changes in GLU content, and serum LH (p < 0.001) and leptin (p < 0.0001) decreased significantly. In summary, current studies have demonstrated that LPS administration to 15- and 30-day-old female rats results in a different response of the hypothalamus-pituitary-gonadal axis and of the adipose tissue, demonstrating an ontogenic response of the immune-neuroendocrine system to LPS administration.
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- 2008
17. Leptin Stimulates the Reproductive Male Axis in Rats during Sexual Maturation by Acting on Hypothalamic Excitatory Amino Acids
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Jaime A. Moguilevsky, Roxana Reynoso, Pablo Scacchi, Dora Rondina, Berta Szwarcfarb, Rimoldi G, Osvaldo J. Ponzo, and Silvia Carbone
- Subjects
Leptin ,Male ,medicine.medical_specialty ,Endocrinology, Diabetes and Metabolism ,Hypothalamus ,Radioimmunoassay ,Glutamic Acid ,Biology ,Gonadotropin-Releasing Hormone ,chemistry.chemical_compound ,Endocrinology ,Internal medicine ,Internal Medicine ,medicine ,Animals ,Sexual maturity ,Sexual Maturation ,Amino Acids ,Chromatography, High Pressure Liquid ,gamma-Aminobutyric Acid ,chemistry.chemical_classification ,Aspartic Acid ,Glutamate receptor ,General Medicine ,Luteinizing Hormone ,Rats ,Amino acid ,chemistry ,Amino acid neurotransmitter ,Excitatory postsynaptic potential ,hormones, hormone substitutes, and hormone antagonists ,Hormone - Abstract
The purpose of the present study was to determine the effect of treatment with leptin on gonadotrophin secretion and hypothalamic GnRH, excitatory and inhibitory amino acids release, in prepubertal (15 days old) and peripubertal (30 days old) male rats. Rats of both ages received a single (ip) injection of 30 microg/kg leptin 60 minutes previous to sacrifice. Serum LH was determined, and the hypothalamus dissected and incubated in Earle's medium. GnRH and amino acids release were determined in the media. LH and GnRH were measured by RIA. Amino acids were assessed by HPLC-UV detection. In the two prepubertal stages, (prepubertal and peripubertal, 15 and 30 days of age respectively) leptin increased plasmatic LH levels (p < 0.01) and hypothalamic GnRH release (p < 0.01). Glutamate (GLU) release showed an increment in leptin-treated rats (p < 0.01) at both ages, while only the 30 days old rats showed an increment of the aspartate (ASP) release. GABA secretion was not modified by leptin treatment. In conclusion, the results demonstrated that leptin stimulates the LH-GnRH axis during sexual development in male rats, increasing the secretion of both hormones. The hypothalamic excitatory amino acid neurotransmitter system appears to be involved in this change.
- Published
- 2005
18. Leptin Stimulates LH Secretion in Peripubertal Male Rats Through NMDA Receptors
- Author
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Roxana Reynoso, Pablo Scacchi, Jaime Moguilevsky, Berta Szwarcfarb, Osvaldo J. Ponzo, Dora Rondina, Silvia Carbone, and Gabriela Bollero
- Subjects
Leptin ,Male ,medicine.medical_specialty ,Hypothalamus ,Glutamic Acid ,Peptide hormone ,Biology ,Neurotransmission ,Receptors, N-Methyl-D-Aspartate ,Endocrinology ,Internal medicine ,medicine ,Animals ,Sexual Maturation ,Rats, Wistar ,gamma-Aminobutyric Acid ,Antagonist ,Glutamate receptor ,General Medicine ,Luteinizing Hormone ,Rats ,Neuroprotective Agents ,Excitatory postsynaptic potential ,NMDA receptor ,Dizocilpine Maleate ,Hormone - Abstract
Leptin, a peptide hormone secreted by adipocytes that has been proposed as a metabolic signal in the reproductive system, appears to be linked to the different neuroendocrine processes involved in the onset of puberty. We studied the ontogenic effect of administration of leptin (30 mg/kg i.p.) on serum LH levels during different stages of sexual development (7, 30, and 45 days of age) in male rats and on the hypothalamic content of glutamate (GLU) and gamma-aminobutyric acid (GABA) in 30-day-old rats. Leptin induced a significant increase (p0.01) in LH levels in 30 days old rats. This hormone stimulatory effect was accompanied by a significant enhancement (p0.01) of the hypothalamic content of glutamate, the hypothalamic excitatory aminoacid involved in N-methyl-D-aspartate (NMDA) neurotransmission. No changes in the LH plasma levels were observed in 7- and 45-day-old male rats treated with leptin. MK 801 (0.1 and 0.3 mg/kg i.p.), an antagonist of NMDA receptors of excitatory amino acid system (EAAs), antagonized the stimulatory effect of leptin on LH secretion and on the hypothalamic content of GLU. These results demonstrate that leptin stimulates the reproductive axis in male rats during a determined period of sexual maturation and that NMDA receptors are involved in thefacilitatory action of leptin on the gonadal axis of male rats during sexual maturation.
- Published
- 2005
19. Psychiatric worker and family members: pathways towards co-operation networks within psychiatric assistance services
- Author
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Silvia Carbone
- Subjects
medicine.medical_specialty ,lcsh:RC435-571 ,Institutionalisation ,mental ,lcsh:Medicine ,Mindset ,Community service ,Article ,family care ,Co operation ,Resource (project management) ,healthcare worker ,Nursing ,lcsh:Psychiatry ,Medicine ,In patient ,Psychiatry ,sociology ,Health professionals ,business.industry ,lcsh:R ,Mental health ,Psychiatry and Mental health ,business ,mental health ,mental health, healthcare worker, sociology, mental, family care - Abstract
The family's role in patient care was greatly altered by Law 180. This law, introduced in Italy in 1978, led to a gradual phasing out of custodial treatment for psychiatric patients. This different mindset, which views the family as an alternative to institutionalization, leads to it being seen as an essential entity in the setting up of community service dynamics. We interviewed health professionals in order to understand obstacles of collaboration between family members and mental health care workers. The goal was to uncover actions that promote collaboration and help build alliances between families and psychiatric workers. Results showed that health professionals view the family as a therapeutic resource. Despite this view, family members were rarely included in patient treatment. The reasons is: the structures have a theoretical orientation of collaboration with the family but, for nurses not are organized a few meeting spaces with family members. Services should create moments, such as multi-family groups or groups of information, managed by nurses and not only by doctors. These occasions it might facilitate the knowledge between professionals and family members.
- Published
- 2014
20. Interrelationships of GABAergic, Serotoninergic and Excitatory Amino Acid Systems in its Regulatory Effect on Prolactin Secretion in Prepubertal Rats
- Author
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Silvia Carbone, Osvaldo J. Ponzo, Dora Rondina, Berta Szwarcfarb, Pablo Scacchi, and Jaime A. Moguilevsky
- Subjects
Serotonin ,medicine.medical_specialty ,N-Methylaspartate ,medicine.drug_class ,Excitatory Amino Acids ,Hypothalamus ,Biology ,Pharmacology ,Serotonergic ,Receptors, N-Methyl-D-Aspartate ,gamma-Aminobutyric acid ,5-Hydroxytryptophan ,chemistry.chemical_compound ,Endocrinology ,Internal medicine ,medicine ,Animals ,GABA-A Receptor Antagonists ,Sexual Maturation ,p-Chloroamphetamine ,P-Chloroamphetamine ,Neurotransmitter ,gamma-Aminobutyric Acid ,6-Cyano-7-nitroquinoxaline-2,3-dione ,Kainic Acid ,General Medicine ,Receptor antagonist ,Prolactin ,Rats ,Receptors, Glutamate ,chemistry ,GABAergic ,Female ,Dizocilpine Maleate ,GABA-B Receptor Antagonists ,medicine.drug - Abstract
GABAergic, serotoninergic and excitatory amino acid systems (EAAs) regulate the prolactin (PROL) secretion in prepubertal female rats. The aim of the present paper was to determine the interrelationships of these systems on the control of this pituitary hormone. It was carried out through the following scheme: 1. The participation of the EAAs and serotonin in the effect of GABAergic system on PROL release, determined by evaluating the GABA A and GABA B receptor agonists. It was carried out on animals that were previously treated with AAEs receptor antagonist or p-chlorophenylamphetamine (PCA), this one depleting serotonin in the hypothalamus. 2. The participation of GABAergic system in the effect of serotonin and EAAs systems, determined by the evaluation of the effects of EAAs receptor agonists and of 5-HTP, a serotonin precursor. With this purpose the rats were previously treated with GABA A and GABA B receptor antagonists. 3. The interrelationships between the EAAs and the serotoninergic systems in the control of PROL secretion, determined (a) by using EAAs agonists (in rats depleted of serotonin by PCA) and (b) using EAAs antagonists (in rats treated with 5-HTP, a serotonin precursor). The administration of GABAergic agonists significantly increased PROL secretion in prepubertal female rats. Neither EAAs antagonists nor the depletion of serotonin in the brain, modified the stimulatory effects of the GABAergic system on PROL levels. This is a clear indication that the activity of the GABAergic system is independent of the serotoninergic and of the EAAs system effects on the pituitary hormone. The EAAs neurotransmitter system agonists significantly increase PROL levels. This effect was blocked by the GABAergic system antagonists but was not modified by serotonin depletion. Taking into account these facts it may be considered that the GABAergic system is involved in the stimulatory effect of EAAs on PROL secretion, this effect being independent of the serotoninergic system. 5-HTP significantly increased PROL plasma levels, and this effect was modified neither by the GABAergic nor by the EAAs receptor antagonists. These results indicate that the stimulatory effect of serotonin on PROL release is independent of the GABAergic and EAAs systems. In conclusion it may be considered that in prepubertal female rats, the GABAergic and serotoninergic systems stimulate PROL secretion by independent mechanisms that do not include EAAs. On the other hand, the effects of EAAs neurotransmission are exerted via the GABAergic system.
- Published
- 2000
21. Effect of an Aproteic Diet on Gonadotropin Release Response to GnRH and Estrogen-Progesterone in Rats
- Author
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Pablo Scacchi, Dora Rondina, Silvia Carbone, Berta Szwarcfarb, Osvaldo J. Ponzo, and Jaime A. Moguilevsky
- Subjects
Male ,endocrine system ,medicine.medical_specialty ,Pituitary gland ,medicine.drug_class ,Ovariectomy ,Stimulation ,Biology ,Feedback ,Gonadotropin-Releasing Hormone ,Basal (phylogenetics) ,Endocrinology ,Pituitary Gland, Anterior ,Protein Deficiency ,Internal medicine ,medicine ,Animals ,Secretion ,Rats, Wistar ,Progesterone ,Estradiol ,General Medicine ,Luteinizing Hormone ,Prolactin ,Rats ,Gonadotropin secretion ,medicine.anatomical_structure ,Estrogen ,Female ,Dietary Proteins ,Follicle Stimulating Hormone ,Gonadotropin ,hormones, hormone substitutes, and hormone antagonists - Abstract
The fasting-induced gonadotropin function decrease is unspecific, because in this situation there is a lack of all nutrients. We report here the effect of specific protein lack in the diet during 21 days, on pituitary gonadotropin synthesis and response to exogenous GnRH in adult male rats. We also studied the effect of the aproteic diet (AP) on the positive feedback mechanism in adult female castrated rats. The AP diet decreased significantly, both LH and FSH pituitary concentration and also basal gonadotropin plasma levels in male rats. GnRH produced a significantly increment in LH secretion in both treated and control groups, reaching similar levels after stimulation. Nevertheless, the percentile increment from basal levels in the aproteic group was almost four times the controls, suggesting an increased sensitivity in pituitary response to GnRH in rats fed with AP diet. In female castrated rats, the aproteic diet imposed 3 weeks after the surgery was unable to reduce basal gonadotropin secretion, and so also prolactin secretion. Estradiol/progesterone (EP) administration produced the activation of positive feedback mechanism, increasing significantly LH and FSH secretion in both controls and AP groups. Nevertheless, both gonadotropin responses to EP were significantly greater in rats fed with AP diet. Basal prolactin levels and response to EP were not different between both groups. This results suggest that selective protein lack in a diet, reduced pituitary LH and FSH synthesis and secretion. This type of diet also increments pituitary sensitivity to GnRH administration in male rats, and gonadotropin response to positive feedback mechanism in female rats.
- Published
- 1999
22. Low dose 4-MBC effect on neuroendocrine regulation of reproductive axis in adult male rats
- Author
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Roxana Reynoso, Silvia Carbone, Maria E. Carou, Jaime A. Moguilevsky, Berta Szwarcfarb, Maria L. Deguiz, Osvaldo J. Ponzo, Pablo Scacchi, and Romina P. Cardozo Gutierrez
- Subjects
Pharmacology ,endocrine system ,medicine.medical_specialty ,Adult male ,Health, Toxicology and Mutagenesis ,Low dose ,General Medicine ,Serum concentration ,Biology ,Toxicology ,In vitro ,Serum prolactin ,Endocrinology ,Hypothalamus ,Internal medicine ,Male rats ,medicine ,hormones, hormone substitutes, and hormone antagonists - Abstract
4-Methylbenzylidene camphor (4-MBC) is an ultraviolet absorbent. The objective of this paper was to evaluate the effect of 4-MBC low-dose exposure on the neuroendocrine reproductive regulation in male rats. Wistar male adult rats were injected sc. with 4-MBC during 5 days with a dose of 2 and 10 mg/kg or during 2 days with a dose of 2 and 20 mg/kg. In all rats serum prolactin, LH and FSH concentration were assayed. The hypothalamus of rats injected during 2 days were also dissected to study GnRH release. Rats that received 2 and 10 mg/kg of 4-MBC during 5 days showed a decrease in the LH and FSH serum concentration. In rats injected during 2 days, serum LH decreased with 2 and 20 mg/kg and FSH decreased with 2 mg/kg of 4-MBC. In vitro hypothalamic GnRH release also decreased in these animals. These results show that low doses of 4-MBC inhibit the reproductive axis in adult male rats.
- Published
- 2008
23. Low dose of bisphenol A impairs the reproductive axis of prepuberal male rats
- Author
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Roxana Reynoso, Nancy Patricia Cardoso, Silvia Carbone, Pablo Scacchi, Romina Penalba, Osvaldo J. Ponzo, Matías Pandolfi, and Juan Manuel Gámez
- Subjects
Male ,endocrine system ,medicine.medical_specialty ,Bisphenol A ,CIENCIAS MÉDICAS Y DE LA SALUD ,Physiology ,Offspring ,Disorders of Sex Development ,Lumen (anatomy) ,Weaning ,Biology ,Endocrine Disruptors ,Biochemistry ,chemistry.chemical_compound ,Phenols ,Pregnancy ,Lactation ,Internal medicine ,Toxicología ,Male rats ,Testis ,medicine ,Animals ,Testosterone ,Sexual Maturation ,Benzhydryl Compounds ,urogenital system ,General Medicine ,Environmental Exposure ,Organ Size ,Luteinizing Hormone ,Prepuberal male rats ,Rats ,Medicina Básica ,medicine.anatomical_structure ,Endocrinology ,Reproductive axis ,Endocrine disruptor ,chemistry ,Pituitary Gland ,Prenatal Exposure Delayed Effects ,Gestation ,Female ,Follicle Stimulating Hormone ,hormones, hormone substitutes, and hormone antagonists - Abstract
The objective of the present work was to study the effect of a low dose of bisphenol A (BPA), on the reproductive axis of prepuberal male rats exposed to the endocrine disruptor (ED) during gestation and lactation period. Wistar-mated rats were treated with either 0.1 % ethanol or BPA in their drinking water until their offspring were weaned at the age of 21 days. The estimated average dose of exposure to dams was approximately 3 μg/kg/day of BPA. The pups were sacrificed on the 35th day of life. Body weight was measured during the development and at the moment of the sacrifice; testicular and seminal vesicles weight and their respective relative weights were also measured. LH, FSH and testosterone were determined and histological studies of testicular tissue were also performed. Body weight at the moment of the sacrifice was significantly higher in the group exposed to BPA; testicular weight decreased significantly; seminal vesicles weight and relative weights of testes and seminal vesicles were not modified by treatment. LH and FSH serum levels increased significantly after treatment, meanwhile testosterone showed no significant changes. Histological studies showed the lumen of seminal tubes reduced by the presence of immature cells of the spermatic lineage. Our results suggest that pre- and early postnatal exposure to a low dose of BPA disrupts the normal function of the reproductive axis in prepuberal male rats. The effects of the ED may be exerted at different levels of the axis and may be dependent on the dose, manner of administration, and the moment of exposure to the disruptor. Fil: Gámez, Juan Manuel. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas; Argentina Fil: Penalba, Romina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas; Argentina Fil: Cardoso, Nancy Patricia. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Ponzo, Osvaldo. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas; Argentina Fil: Carbone, Silvia Elena. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Pandolfi, Matias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental. Laboratorio de Neuroendocrinología y Comportamiento; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Scacchi, Pablo. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires". Facultad de Ciencias Médicas. Departamento de Docencia e Investigación; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Reynoso, Roxana. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas; Argentina. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires". Facultad de Ciencias Médicas. Departamento de Docencia e Investigación; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
- Published
- 2013
24. Effects of aging on N-methyl-d-aspartate (NMDA)-induced GnRH and LH release in female rats
- Author
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Pablo Scacchi, Manuel Rodríguez, Pablo Arias, Silvia Carbone, Jaime A. Moguilevsky, Carlos Feleder, and Berta Szwarcfarb
- Subjects
Agonist ,Aging ,medicine.medical_specialty ,N-Methylaspartate ,medicine.drug_class ,Gonadotropin-releasing hormone ,Neurotransmission ,Biology ,Gonadotropin-Releasing Hormone ,Basal (phylogenetics) ,Internal medicine ,medicine ,Animals ,Rats, Wistar ,Molecular Biology ,General Neuroscience ,Glutamate receptor ,Luteinizing Hormone ,Rats ,Endocrinology ,Excitatory postsynaptic potential ,NMDA receptor ,Female ,Neurology (clinical) ,Gonadotropin ,Developmental Biology - Abstract
In order to evaluate if the changes of the hypothalamic-pituitary-ovary axis that induce a decrease in fertility and modifications in the sexual cycles during senescence involve modifications in the regulatory action of excitatory amino acid neurotransmission on GnRH neurons, we measured the in vitro effects of NMDA on GnRH release by the anterior preoptic and medial basal hypothalamic areas (APOA-MBH) of castrated aging (18 months old) and young (90 days of age) rats. In a second series of experiments the in vivo LH release response to intrahypothalamic (push-pull) administration of NMDA to aged and young castrated female rats was also determined. A similar rate of basal GnRH release was observed in old and young rats during the incubation time. The addition of NMDA to the medium significantly increased GnRH release in both groups; nevertheless, the GnRH release response to NMDA was significantly lower in old (P0.01) than in young rats (Young: Basal: 50 +/- 10; NMDA 15': 410 +/- 63, 22,5': 1,469 +/- 300; Old: Basal: 47 +/- 10; NMDA 15': 210 +/- 30; 22,5': 350 +/- 65 ng/GnRH/mg.protein). The LH levels measured throughout the in vivo experiments indicated that basal LH concentrations were significantly lower in the aged group. The mean LH concentrations (fractions 1 to 6) was significantly lower in the aged group (Young: 3.9 +/- 0.07, Old: 2.4 +/- 0.03 ng/ml, P0.01). The LH release response to NMDA measured 10 min after the intrahypothalamic administration of the glutamate agonist was significantly lower in aged rats (4.2 +/- 1.6 ng/ml) as compared to young animals (18.0 +/- 6.1 ng/ml; P0.05). LH levels in young rats increased to 580% vs., and only 47% in aged rats as compared to previous basal values. In conclusion, present results demonstrate that the GnRH responses to NMDA neurotransmission, which has a predominantly excitatory effects on GnRH neurons, is significantly decreased in old rats, these data give further support to the hypothesis that a decrease in the excitatory inputs to GnRH neurons could be directly involved in the reduction of the hypothalamic-pituitary-ovary axis activity observed during aging.
- Published
- 1996
25. Changes in the Hypothalamic Interaction between Norepinephrine and Prostaglandin E2 during Sexual Maturation in Female Rats
- Author
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Berta Szwarcfarb, Jaime A. Moguilevsky, Silvia Carbone, Martha F. Gimeno, Ana Maria Franchi, and Dora Rondina
- Subjects
medicine.medical_specialty ,Endocrine and Autonomic Systems ,Endocrinology, Diabetes and Metabolism ,Prostanoid ,Metabolism ,Biology ,Norepinephrine (medication) ,Cellular and Molecular Neuroscience ,chemistry.chemical_compound ,Endocrinology ,chemistry ,Internal medicine ,mental disorders ,medicine ,Sexual maturity ,Prostaglandin E2 ,medicine.drug - Abstract
The present experiments describe the study of the metabolism of 14C-arachidonic acid and the effect of exogenous norepinephrine (NE) on prostanoid production in the anterior preop-tic area
- Published
- 1995
26. Different effects by sex on hypothalamic-pituitary axis of prepubertal offspring rats produced by in utero and lactational exposure to di-(2-ethylhexyl) phthalate (DEHP)
- Author
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Rodolfo A. Cutrera, Nancy Patricia Cardoso, Pablo Scacchi, Silvia Carbone, J.A. Moguilevsky, Roxana Reynoso, Y.A. Samaniego, and Osvaldo J. Ponzo
- Subjects
Male ,endocrine system ,medicine.medical_specialty ,Hypothalamo-Hypophyseal System ,medicine.drug_class ,Offspring ,Pituitary-Adrenal System ,Biology ,Toxicology ,Statistics, Nonparametric ,chemistry.chemical_compound ,Plasticizers ,Pregnancy ,Internal medicine ,Diethylhexyl Phthalate ,Testis ,medicine ,Animals ,Lactation ,Rats, Wistar ,Neurotransmitter ,gamma-Aminobutyric Acid ,Aspartic Acid ,Sex Characteristics ,Dose-Response Relationship, Drug ,General Neuroscience ,Uterus ,Glutamate receptor ,Phthalate ,Organ Size ,Luteinizing Hormone ,Rats ,Dose–response relationship ,Endocrinology ,chemistry ,In utero ,Maternal Exposure ,Prenatal Exposure Delayed Effects ,Female ,Hypothalamic pituitary axis ,Gonadotropin ,Follicle Stimulating Hormone ,Gonadotropins - Abstract
This study investigated the effect of pre and perinatal exposure to di-(2-ethylhexyl) phthalate (DEHP) on the neuroendocrine parameters that regulate reproduction in prepubertal male and female rats. DEHP at doses of 3 and 30mg/kgbw/day was administered orally in the drinking water to dam rats since pregnancy onset until the moment of pups sacrifice at 15 days of age. In these animals gonadotropin serum level and the hypothalamic contents of the amino acids aspartate, glutamate and gamma-aminobutyric acid were determined. No changes in gonadotropin levels and amino acid neurotransmitters were detected at the low dose in both sexes. However, DEHP administered at high dose (30mg/kgbw/day) to dams produced a significant decrease in the inhibitory neurotransmitter GABA and an increase in the stimulatory neurotransmitter aspartate in prepubertal male offspring rats. These modifications were accompanied by gonadotropin serum levels increase. On the contrary, in treated female rats this chemical increased both, aspartate and GABA, which exert a characteristic stimulatory action on gonadotropin in 15-day-old normal females. This study provides new data about changes produced by DEHP on the hypothalamic amino acid neurotransmitters involved in the neuroendocrine reproductive regulation, in prepubertal male and female rat offspring from dams exposed during gestational and lactational periods. These alterations induced by DEHP exposure could be related to the gonadotropin modifications also described in this work, and with changes in the production of sexual hormones previously reported by other authors.
- Published
- 2011
27. Probable gamma-aminobutyric acid involvement in bisphenol A effect at the hypothalamic level in adult male rats
- Author
-
Silvia Carbone, Nancy Patricia Cardoso, Osvaldo J. Ponzo, Justina Lavalle, Roxana Reynoso, Pablo Scacchi, and Matías Pandolfi
- Subjects
Germinal epithelium ,Male ,endocrine system ,medicine.medical_specialty ,Bisphenol A ,Physiology ,Offspring ,Period (gene) ,Hypothalamus ,Biology ,Biochemistry ,gamma-Aminobutyric acid ,Gonadotropin-Releasing Hormone ,chemistry.chemical_compound ,Phenols ,Pregnancy ,Internal medicine ,Testis ,medicine ,Animals ,Testosterone ,Benzhydryl Compounds ,Rats, Wistar ,gamma-Aminobutyric Acid ,Ethanol ,Leydig Cells ,General Medicine ,Rats ,Endocrinology ,chemistry ,Cytoarchitecture ,Prenatal Exposure Delayed Effects ,Female ,Follicle Stimulating Hormone ,Gonadotropins ,medicine.drug - Abstract
The aim of the present study was to investigate the effects of bisphenol A (BPA) on the neuroendocrine mechanism of control of the reproductive axis in adult male rats exposed to it during pre- and early postnatal periods. Wistar mated rats were treated with either 0.1% ethanol or BPA in their drinking water until their offspring were weaned at the age of 21 days. The estimated average dose of exposure to dams was approximately 2.5 mg/kg body weight per day of BPA. After 21 days, the pups were separated from the mother and sacrificed on 70 day of life. Gn-RH and gamma-aminobutyric acid (GABA) release from hypothalamic fragments was measured. LH, FSH, and testosterone concentrations were determined, and histological and morphometrical studies of testis were performed. Gn-RH release decreased significantly, while GABA serum levels were markedly increased by treatment. LH serum levels showed no changes, and FSH and testosterone levels decreased significantly. Histological studies showed abnormalities in the tubular organization of the germinal epithelium. The cytoarchitecture of germinal cells was apparently normal, and a reduction of the nuclear area of Leydig cells but not their number was observed. Taken all together, these results provide evidence of the effect caused by BPA on the adult male reproductive axis when exposed during pre- and postnatal period. Moreover, our findings suggest a probable GABA involvement in its effect at the hypothalamic level.
- Published
- 2010
28. Evidence to suggest glutamic acid involvement in Bisphenol A effect at the hypothalamic level in prepubertal male rats
- Author
-
Nancy, Cardoso, Matías, Pandolfi, Osvaldo, Ponzo, Silvia, Carbone, Berta, Szwarcfarb, Pablo, Scacchi, and Roxana, Reynoso
- Subjects
Male ,Hypothalamus ,Radioimmunoassay ,Glutamic Acid ,Luteinizing Hormone ,Rats ,Gonadotropin-Releasing Hormone ,Phenols ,Pregnancy ,Prenatal Exposure Delayed Effects ,Animals ,Female ,Testosterone ,Sexual Maturation ,Benzhydryl Compounds ,Follicle Stimulating Hormone ,Rats, Wistar ,Chromatography, High Pressure Liquid - Abstract
The aim of present paper was to study the probable role of glutamic acid (GLU) as a mediator of bisphenol A (BPA) effect at the hypothalamic level and its effects on the reproductive axis of prepubertal male rats.Mated Wistar rats were treated with either 0.1% ethanol (control group, n=10) or BPA (BPA group, n=10) in their drinking water until their offspring were weaned at the age of 21 days. The estimated average dose of exposure to dams was approximately 2.5 mg/kg body weight/day of BPA. At the prepubertal stage (35 days of age), the male rats were sacrificed and Gn-RH and glutamic acid (GLU) release, an amino acid involved in Gn-RH secretion, were measured in hypothalamic samples containing medio basal and anterior preoptic area (MBH-APOA), by RIA and HPLC respectively. LH, FSH serum levels were measured by RIA and testosterone by EQLIA.Gn-RH and GLU release decreased significantly in animals exposed to BPA (p0.001, p0.01). LH, FSH and testosterone serum levels were also decreased by treatment (p0.0001).Present results provide evidence that BPA may act at the hypothalamic level to decrease GLU release which in turn may modify Gn-RH secretion altering the normal function of the axis.
- Published
- 2010
29. Impact of gestational and lactational phthalate exposure on hypothalamic content of amino acid neurotransmitters and FSH secretion in peripubertal male rats
- Author
-
Pablo Scacchi, Berta Szwarcfarb, Jaime A. Moguilevsky, Laura Deguiz, Nancy Patricia Cardoso, Silvia Carbone, Roxana Reynoso, and Osvaldo J. Ponzo
- Subjects
Male ,endocrine system ,medicine.medical_specialty ,CIENCIAS MÉDICAS Y DE LA SALUD ,medicine.drug_class ,Offspring ,Hypothalamus ,PHTALATE ,Biology ,Fisiología ,Toxicology ,GESTATIONAL ,RATS ,GABA ,chemistry.chemical_compound ,Follicle-stimulating hormone ,Pregnancy ,Internal medicine ,Diethylhexyl Phthalate ,medicine ,Animals ,Lactation ,ASPARTATE ,Sexual Maturation ,Amino Acids ,Rats, Wistar ,Neurotransmitter ,gamma-Aminobutyric Acid ,chemistry.chemical_classification ,Aspartic Acid ,Neurotransmitter Agents ,General Neuroscience ,Phthalate ,Amino acid ,Rats ,Medicina Básica ,Endocrinology ,LACTATIONAL ,chemistry ,GONADOTROPIN ,Prenatal Exposure Delayed Effects ,Female ,Gonadotropin ,Follicle Stimulating Hormone ,Breast feeding ,hormones, hormone substitutes, and hormone antagonists - Abstract
This study investigated the effect of the pre- and perinatal exposure to di-(2-ethylhexyl) phthalate (DEHP) on the neuroendocrine parameters that regulate reproduction in peripubertal male rats. DEHP at dose of 3 and 30 mg/kg. bw/day was administered orally to female rat since pregnancy onset until weaning. The male litters were sacrificed at 30 days of age to determine gonadotropin serum level and the hypothalamic contents of the amino acids aspartate and gamma-aminobutyric acid. No changes in gonadotropin, aspartate and gamma-aminobutyric acid levels were detected at the low dose. DEHP 30 mg/kg. bw/day reduced testis weight and serum FSH, in correlation with a significant increase in the inhibitory GABAergic tone and a reduction in the stimulatory effect of aspartate on gonadotropin level. This study provides unknown data regarding changes in the hypothalamic contents of the amino acid neurotransmitters, which are involved in the neuroendocrine regulation of reproductive axis, in peripubertal male rat offspring from dams exposed to DEHP during gestational and lactational periods. This could be related with the gonadotropin modifications also here described. Fil: Carbone, Silvia Elena. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Endocrinología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina Fil: Szwarcfarb, Berta. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Endocrinología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina Fil: Ponzo, Osvaldo Juan. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Endocrinología; Argentina Fil: Reynoso, Roxana María. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Endocrinología; Argentina Fil: Cardoso, Nancy Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Endocrinología; Argentina Fil: Deguiz, Laura. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Endocrinología; Argentina Fil: Moguilevsky, Jaime Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Fundación Favaloro; Argentina Fil: Scacchi, Pablo. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Endocrinología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina
- Published
- 2010
30. Changes in the effect of gamma-aminobutyric acid on prolactin secretion during sexual maturation in female rats
- Author
-
Berta Szwarcfarb, Silvia Carbone, and Jaime A. Moguilevsky
- Subjects
Agonist ,Aging ,Baclofen ,endocrine system ,medicine.medical_specialty ,medicine.drug_class ,Hypothalamus ,Stimulation ,Biology ,gamma-Aminobutyric acid ,chemistry.chemical_compound ,Endocrinology ,Internal medicine ,medicine ,Animals ,Sexual Maturation ,gamma-Aminobutyric Acid ,Muscimol ,GABAA receptor ,Aminooxyacetic Acid ,Rats, Inbred Strains ,Receptors, GABA-A ,Aminooxyacetic acid ,Prolactin ,Rats ,nervous system ,chemistry ,4-Aminobutyrate Transaminase ,Female ,hormones, hormone substitutes, and hormone antagonists ,medicine.drug - Abstract
To evaluate the effects of the gamma-aminobutyric acid (GABA)ergic system on PRL secretion during sexual development in female rats, aminooxyacetic acid (an inhibitor of GABA-transaminase which increases the hypothalamic GABA concentration) was administered to 12- to 16- and 30-day-old female rats. The increased GABA level in the hypothalamus was accompanied by a significant increase in the serum PRL concentration in rats 16 days of age and a decrease in the serum concentration of the hormone in 30-day-old rats. No changes in PRL levels were observed at 12 days of age. Muscimol, a GABA-A receptor agonist, increased serum PRL concentrations in 16-day-old rats. By contrast, in rats 30 days of age, muscimol induced a significant decrease in PRL levels. On the other hand, the administration of baclofen, a GABA-B receptor agonist, induced a pattern of PRL modification similar to that observed with muscimol, i.e. stimulation in rats 16 days of age and inhibition in 30-day-old rats. These findings indicate that both the stimulatory and inhibitory effects of the GABAergic system on PRL secretion during sexual maturation are mediated by GABA-A and GABA-B receptors. The present results show that during sexual maturation there is a qualitative modification of the effect of the GABAergic system on PRL secretion. These findings could be related to the complex neuroendocrine mechanisms involved in the onset of puberty in the female rat.
- Published
- 1992
31. Effects of ovarian steroids on the gonadotropin response to N-methyl-D-aspartate and on hypothalamic excitatory amino acid levels during sexual maturation in female rats
- Author
-
Silvia Carbone, Jaime A. Moguilevsky, Berta Szwarcfarb, and M. E. Otero Losada
- Subjects
medicine.medical_specialty ,N-Methylaspartate ,medicine.drug_class ,Glycine ,Hypothalamus ,Glutamic Acid ,Gonadotropin-releasing hormone ,Biology ,Gonadotropin-Releasing Hormone ,Follicle-stimulating hormone ,Endocrinology ,Glutamates ,Internal medicine ,medicine ,Animals ,Sexual Maturation ,Amino Acids ,Progesterone ,Aspartic Acid ,Alanine ,Ovary ,Estrogens ,Rats, Inbred Strains ,Luteinizing Hormone ,Preoptic Area ,Rats ,Gonadotropin secretion ,Preoptic area ,nervous system ,NMDA receptor ,Female ,Follicle Stimulating Hormone ,Gonadotropin ,Luteinizing hormone ,Gonadotropins ,hormones, hormone substitutes, and hormone antagonists - Abstract
In order to evaluate the involvement of estrogen-progesterone (EP) in the effects of N-methyl-D-aspartate (NMDA) receptor stimulation on gonadotropin secretion during sexual development in female rats, NMDA (30 mg/kg sc) was administered to 16- and 30-day-old female rats pretreated with EP. NMDA administration induced increases in plasma LH concentration that were 13.6-fold and 94.5-fold higher, respectively, than those found after NMDA alone. The increase of LH levels induced by NMDA was accompanied by a significant enhancement of the content of GnRH in the anterior and preoptic hypothalamic areas and in the medial basal hypothalamus (APOA/MBH). EP potentiated this increase of GnRH induced by NMDA. NMDA increased plasma FSH levels at 16 days of age, and this increase was inhibited by EP treatment. In 30-day-old rats EP induced FSH release in response to NMDA. This release was not observed in rats treated only with NMDA. In 16-day-old rats EP induced an increase in the concentrations of aspartate, glutamate, and glycine in the anterior and preoptic hypothalamic areas and in the medial basal hypothalamus, the excitatory amino acids involved in NMDA neurotransmission. This effect was not observed in rats of 30 days of age. In summary, the present results show that during sexual maturation ovarian steroids potentiated the LH-releasing response to NMDA probably by acting at the hypothalamic level; furthermore, during sexual maturation there are changes in the response to EP of the hypothalamic concentrations of excitatory amino acids. These findings could be related to the neuroendocrine mechanisms regulating the onset of puberty and the sexual cycle in female rats.
- Published
- 1992
32. Sexual maturation modifies the GABAergic control of gonadotrophin secretion in female rats
- Author
-
Berta Szwarcfarb, Dora Rondina, Jaime A. Moguilevsky, and Silvia Carbone
- Subjects
Baclofen ,endocrine system ,medicine.medical_specialty ,medicine.drug_class ,Biology ,Bicuculline ,chemistry.chemical_compound ,Follicle-stimulating hormone ,Internal medicine ,medicine ,Animals ,Sexual Maturation ,Molecular Biology ,gamma-Aminobutyric Acid ,Muscimol ,GABAA receptor ,General Neuroscience ,Aminooxyacetic Acid ,Rats, Inbred Strains ,Luteinizing Hormone ,Receptors, GABA-A ,Aminooxyacetic acid ,Rats ,Endocrinology ,nervous system ,chemistry ,GABAergic ,Female ,Neurology (clinical) ,Follicle Stimulating Hormone ,Gonadotropin ,Luteinizing hormone ,Gonadotropins ,Developmental Biology ,medicine.drug - Abstract
Administration of aminooxyacetic acid, (an inhibitor of γ-aminobutyric acid (GABA)-transaminase which enhances the hypothalamic GABA content) increased luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels in prepubertal rats (16 days of age), and decreased the levels of these pituitary hormones in peripubertal rats (30 days of age). Prepubertal and peripubertal female rats were administered with muscimol, a GABAA-antagonist, with baclofen, a GABAB agonist, and with bicuculline, a GABA-antagonist, and the serum concentrations of LH and FSH were determined. In prepubertal rats, muscimol increased both LH and FSH levels, while in peripubertals the GABAA agonist showed the opposite effect, i.e. both gonadotrophins were decreased after its administration. Baclofen lowered serum concentrations of LH and FSH at the different ages studied. Administration of bicuculline produced a decrease in LH and FSH concentrations in prepubertal rats, and an increase of these values in peripubertal rats. These results indicate that GABA exerts a stimulatory tone on gonadotrophin secretion in prepubertal rats and an inhibitory one in peripubertal animals. This effect is most probably mediated by GABAA receptors. It is suggested that the change in the effect on gonadotrophin secretion of the activation of GABAA receptors which takes place during sexual maturation in the female rats is related to the central mechanisms involved in the onset of puberty.
- Published
- 1991
33. Effect of bacterial lipopolysaccharide on the reproductive axis of prepubertal and peripubertal female rats. Ontogenic changes in the immune-neuroendocrine interactions
- Author
-
Roxana, Reynoso, Osvaldo, Ponzo, Nancy, Cardoso, Berta, Szwarcfarb, Silvia, Carbone, Jaime, Moguilevsky, and Pablo, Scacchi
- Subjects
Leptin ,Lipopolysaccharides ,Aging ,Hypothalamo-Hypophyseal System ,Neuroimmunomodulation ,Reproduction ,Hypothalamus ,Glutamic Acid ,Bacterial Infections ,Luteinizing Hormone ,Neurosecretory Systems ,Rats ,Up-Regulation ,Gonadotropin-Releasing Hormone ,Adipose Tissue ,Stress, Physiological ,Animals ,Female ,Sexual Maturation ,Inflammation Mediators ,Nitric Oxide Synthase ,Rats, Wistar ,gamma-Aminobutyric Acid - Abstract
The immune, endocrine and nervous systems are closely interrelated, which allows the organism to respond to different types of stress such as infection. Chronic infectious and inflammatory conditions are often accompanied by an impaired reproductive function. Leptin, a hormone produced by adipose tissue, exerts a regulatory function on the reproductive axis. It has homology with other proinflammatory cytokines and could be modified by lipopolysaccharide (LPS). Therefore, these studies were designed to investigate the effect of LPS administration on the neuroendocrine mechanisms involved in the regulation of the reproductive axis during sexual maturation. Fifteen- and 30-day-old female rats were injected with a single dose of LPS 250 microg/kg (i.p.) and then nitric oxide synthase (NOS) activity, hypothalamic excitatory/inhibitory amino acids and Gn-RH content, serum LH and leptin concentration were studied. In 15-day-old female rats LPS treatment did not modify hypothalamic inducible (iNOS) and constitutive (cNOS) NOS activity, Gn-RH, glutamate (GLU) and GABA content. Also serum LH and leptin levels were not modified. In 30-day-old rats LPS increased iNOS and cNOS activity (p0.001) and hypothalamic Gn-RH content (p0.001). At this age hypothalamic GABA content was significantly decreased (p0.001) without changes in GLU content, and serum LH (p0.001) and leptin (p0.0001) decreased significantly. In summary, current studies have demonstrated that LPS administration to 15- and 30-day-old female rats results in a different response of the hypothalamus-pituitary-gonadal axis and of the adipose tissue, demonstrating an ontogenic response of the immune-neuroendocrine system to LPS administration.
- Published
- 2008
34. In vivo and in vitro studies on the effect of the serotorinergic system on luteinizing hormone and luteinizing hormone-releasing hormone secretion in prepubertal and peripubertal female rats
- Author
-
Pablo Arias, Jaime A. Moguilevsky, Sverdlik Rc, Dora Rondina, Berta Szwarcfarb, and Silvia Carbone
- Subjects
Serotonin ,medicine.medical_specialty ,Hypothalamus ,Methyltyrosines ,Gonadotropic cell ,Serotonergic ,Potassium Chloride ,5-Hydroxytryptophan ,Gonadotropin-Releasing Hormone ,Norepinephrine (medication) ,chemistry.chemical_compound ,In vivo ,Internal medicine ,medicine ,Animals ,Molecular Biology ,General Neuroscience ,Rats, Inbred Strains ,Luteinizing Hormone ,Rats ,alpha-Methyltyrosine ,Endocrinology ,chemistry ,Female ,Neurology (clinical) ,Luteinizing hormone ,Developmental Biology ,medicine.drug ,Hormone - Abstract
The present investigations were designed to assess the effect of the serotoninergic system on luteinizing hormone (LH) and LH-releasing hormone (LH-RH) secretion in female rats aged 14 and 30 days. The administration of 5-hydroxytryptophan (5-HTP; 75 mg/kg i.p.) increased hypothalamic serotonin (5-HT) concentrations in both age groups, and did not affect hypothalamic norepinephrine (NE) concentration or release. Serum LH levels were raised by 5-HTP in 14-day-old, but not in 30-day-old rats. Basal and KC1- (28 mM) stimulated LH-RH release by incubated hypothalamic fragments was significantly enhanced when 5-HTP was injected previously to 14-day-old animals. In 30-day-old rats, 5-HTP treatment did not modify basal LH-RH release, and decreased the KC1-stimulated LH-RH output. Similarly, the addition of 5-HT (10−7M) to superfused hypothalamic fragments enhanced basal LH-RH release in 14-day-old rats and blocked the increment in LH-RH release evoked by KC1 in 30-day-old rats. the present results show that in 14-day-old female rats, the serotoninergic system (activated in vivo by 5-HTP treatment, or in vitro by 5-HT addition) exerts a stimulatory effect on LH-RH, and thus, on LH release. On the contrary, in 30-day-old animals, stimulated LH-RH secretion was inhibited by 5-HT. Apparently, the hypothalamic NE system is not implicated in this response. The participation of this changing effect of 5-HT on LH-RH/LH release at the onset of puberty is postulated.
- Published
- 1990
35. Modulatory Effect of Testosterone on the Serotoninergic Control of Prolactin Secretion in Prepubertal Rats
- Author
-
Sergio N. Justo, Jaime A. Moguilevsky, Berta Szwarcfarb, Pablo Scacchi, Silvia Carbone, and Graciela Justo
- Subjects
Male ,Serotonin ,endocrine system ,medicine.medical_specialty ,medicine.drug_class ,Endocrinology, Diabetes and Metabolism ,Biology ,5-Hydroxytryptophan ,Cellular and Molecular Neuroscience ,chemistry.chemical_compound ,Endocrinology ,Internal medicine ,medicine ,Animals ,Sexual maturity ,Testosterone ,Sexual Maturation ,Neurotransmitter ,Sex Characteristics ,Endocrine and Autonomic Systems ,Rats, Inbred Strains ,Androgen ,Prolactin ,Rats ,Castration ,chemistry ,Prepubertal stage ,Female ,hormones, hormone substitutes, and hormone antagonists ,Hormone - Abstract
The administration of 5-hydroxytryptophan (5-HTP) induced a prolactin release in male and female prepubertal rats at 20 days of age. This response was significantly higher in male than in female rats. Neonatal androgenization of the females significantly increased the release of prolactin induced by 5-HTP treatment compared to the values observed in males; thus, the neonatal exposure to androgens seems to be responsible for the sexual differences in the prolactin response to 5-HTP. In a second series of experiments the effect of this serotoninergic precursor on prolactin release in prepubertal (16, 26, and 30 days of age), peripubertal (45-day-old) and adult male rats was studied. Castration significantly decreased the prolactin release response to 5-HTP in prepubertal rats. The administration of testosterone to castrated rats markedly increased the prolactin release response to 5-HTP. Neither castration nor testosterone administration modified the prolactin response to 5-HTP in peripubertal and adult rats. These results appear to indicate that testosterone modulates the serotoninergic control of prolactin secretion during the prepubertal stage. The control of prolactin levels could be one of the mechanisms by which testosterone participates in the sexual maturation.
- Published
- 1990
36. Nitric oxide synthase inhibition prevents leptin induced Gn-RH release in prepubertal and peripubertal female rats
- Author
-
Roxana Reynoso, Osvaldo J. Ponzo, Jaime A. Moguilevsky, Berta Szwarcfarb, Pablo Scacchi, Silvia Carbone, and Nancy Patricia Cardoso
- Subjects
Leptin ,medicine.medical_specialty ,Endocrinology, Diabetes and Metabolism ,Adipokine ,Stimulation ,Nitric Oxide ,Gonadotropin-Releasing Hormone ,chemistry.chemical_compound ,Endocrinology ,Internal medicine ,Internal Medicine ,medicine ,Animals ,Sexual Maturation ,Amino Acids ,Rats, Wistar ,Neurotransmitter ,omega-N-Methylarginine ,biology ,Glutamate receptor ,General Medicine ,Rats ,Preoptic area ,Nitric oxide synthase ,chemistry ,Hypothalamus ,biology.protein ,Female ,Nitric Oxide Synthase - Abstract
The aim of the present paper was to study the role of NO as a mediator of leptin action at the hypothalamic level during sexual maturation. First, we analyzed the effect of different leptin concentrations (10 -13 , 10 -11 and 10 -9 M) on Gn-RH release from anterior preoptic area and medio basal hypothalamus (APOA-MBH) of prepubertal (15 days old) and peripubertal (30 days old) female rats. Leptin 10 -13 M was the most effective concentration in releasing Gn-RH in both groups of animals. Since glutamate (GLU) and GABA are involved in the hypothalamic control of Gn-RH neurons and also in the neuroendocrine mechanism of puberty, in a second serie of experiments, we evaluated the effect of a competitive inhibitor of nitric oxide synthase (NOS), N-monomethyl-L-arginine (NMMA) on Gn-RH, GLU and GABA release in response to leptin. Co incubation of APOA-MBH with NMMA 0.5 mM, completely blocked Gn-RH and GLU release induced by leptin 10 -13 M in prepubertal and peripubertal rats. NMMA also blocked the stimulation of GABA release in prepubertal rats, as well as the inhibition of GABA release induced by leptin in peripubertal rats. It can be proposed that the different effect of NO on GABA release, could be related to ontogenic changes, e.g, maturation of receptors and/or interneuronal connections during sexual development. Present results provide evidence that leptin acts at the hypothalamic level to stimulate NO release, which in turn modifies the release of amino acid neurotransmitters involved in Gn-RH control.
- Published
- 2007
37. Effect of leptin on LH levels and hypothalamic release of GnRH. Its relationship with the hypothalamic neurotransmitter amino acids system in adult male rats
- Author
-
Berta Szwarcfarb, Silvia Carbone, Osvaldo J. Ponzo, Pablo Scacchi, Dora Rondina, Jaime A. Moguilevsky, and Roxana Reynoso
- Subjects
Leptin ,Male ,medicine.medical_specialty ,Adult male ,Hypothalamus ,Glutamic Acid ,Gonadotropin-Releasing Hormone ,chemistry.chemical_compound ,Endocrinology ,Internal medicine ,Male rats ,medicine ,Animals ,Sexual Maturation ,Rats, Wistar ,Neurotransmitter ,gamma-Aminobutyric Acid ,chemistry.chemical_classification ,biology ,Dose-Response Relationship, Drug ,Excitatory amino-acid transporter ,General Medicine ,Luteinizing Hormone ,Amino acid ,Rats ,chemistry ,biology.protein - Abstract
The objective of the present paper was to determine the effect of leptin on the reproductive axis in adult male rats, as well as the hypothalamic mechanisms involved in this effect. For this purpose, we studied the in vivo effect of leptin in adult male rats on serum LH levels, and the in vitro effect on hypothalamic GnRH and amino acid neurotrasmitter release. For in vivo experiments, animals were injected i.p. with leptin at a dose of 30, 100 and 300 microg/kg. In the in vitro experiments, hypothalamic samples were incubated for 60 min in Earle's medium with leptin: 10(-9), 10(-10) and 10(-12) M for GnRH determination, and 10(-10) M for amino acids evaluation. Finally, we studied the effect of the lowest effective leptin dose on plasma LH levels in peripubertal male rats to compare the effect between this group and adults. Leptin induces significant decreases of serum LH levels with the different studied doses (p0.01 vs. control) in adult male rats, while in peripubertal male rats, it induced a significant (p0.01 vs. control) increment in serum LH levels. On the other hand, in vitro leptin in adult male rats, significantly decreases GnRH release as well as the hypothalamic release of glutamate (GLU). In contrast, leptin increased the GABA release by this hypothalamus in these animals. These results indicate that leptin has an inhibitory effect on the GnRH-LH axis in adult male rats and this effect appears to be connected with an inhibition of hypothalamic release of GLU (the excitatory amino acid) and a stimulatory effect on GABA release (the inhibitory amino acid). On the other hand, in peripubertal male rats, leptin showed a stimulatory effect.
- Published
- 2004
38. Hypothalamic nitric oxide synthase activity during sexual maturation in female rats. Effects of estrogens
- Author
-
Roxana, Reynoso, Claudia, Mohn, Berta, Szwarcfarb, Osvaldo, Ponzo, Silvia, Carbone, Pablo, Scacchi, and Jaime A, Moguilevsky
- Subjects
Estradiol ,Hypothalamus ,Animals ,Female ,Sexual Maturation ,Rats, Wistar ,Synaptic Transmission ,Rats - Abstract
To determine the hypothalamic activity of nitric oxide synthase (NOS, the enzyme involved in the synthesis of nitric oxide NO) during sexual maturation in prepubertal (15 days old) and peripubertal female rats (30 days old) as well as the effect of estradiol administration on this neurotransmitter system.Hypothalamic samples containing the anterior preoptic and medial basal areas (APOA-MBH) were homogenized with HEPES 20 mM, pH = 7.4 and NOS activity was determined in APO-MBH after 10 minutes of incubation by the conversion of 14C arginine to 14C citrulline.The hypothalamic concentration of NOS is significantly higher in peripubertal than in prepubertal rats. Treatment with EB increased significantly the activity of the enzyme in both groups compared with control and the increases was similar at both ages.These results clearly demonstrated that the hypothalamic NOS activity increases in peripubertal rats as compared with prepubertal animals. Estradiol has a similar stimulatory effect on hypothalamic NOS activity at both ages of sexual maturation, indicating that the increase in NOS during sexual maturation is connected with the peripubertal increase of estradiol rather than an increase in the sensitivity of the enzyme to the ovarian hormone.
- Published
- 2004
39. Effect of leptin on hypothalamic release of GnRH and neurotransmitter amino acids during sexual maturation in female rats
- Author
-
Jaime A. Moguilevsky, Dora Rondina, Silvia Carbone, Osvaldo J. Ponzo, Rimoldi G, Roxana Reynoso, Pablo Scacchi, and Berta Szwarcfarb
- Subjects
Leptin ,medicine.medical_specialty ,Endocrinology, Diabetes and Metabolism ,Hypothalamus ,Biology ,Peptide hormone ,Neurotransmission ,Gonadotropin-Releasing Hormone ,chemistry.chemical_compound ,Endocrinology ,Adipocyte ,Internal medicine ,Internal Medicine ,medicine ,Animals ,Sexual Maturation ,Amino Acids ,Rats, Wistar ,Neurotransmitter ,Neurotransmitter Agents ,Glutamate receptor ,General Medicine ,Rats ,chemistry ,NMDA receptor ,Female ,hormones, hormone substitutes, and hormone antagonists - Abstract
The purpose of the present study was to analyse the effect of leptin treatment on the hypothalamic release of GnRH, GABA, and the excitatory amino acids (EAA), aspartate (ASP) and glutamate (GLU) involved in NMDA neurotransmission in prepubertal (15 day old) and peripubertal (30 day old) female rats. The animals were treated with a single dose of leptin (30 microg/kg i.p.) and sacrificed 60 min later. Hypothalamic samples were incubated in Earle's medium; GnRH was determined by RIA and GLU, ASP and GABA by HPLC by UV detection. The hypothalamic release of GnRH was increased by leptin at both ages, the release being significantly higher in peripubertal than in prepubertal rats. The levels of hypothalamic GABA release were different in the two groups; whereas in prepubertal rats the hypothalamic release of GABA increased with leptin administration, the neurotransmitter release decreased in the peripubertal group. On the other hand, the release of ASP was modified only in the peripubertal group, where leptin significantly increased its hypothalamic release. No modifications in leptin-induced hypothalamic release of GLU were observed at the two ages studied. In conclusion, the results showed that leptin increased GnRH release by the hypothalamus of prepubertal and peripubertal rats. In peripubertal rats this increase was accompanied by a significant decrease in the hypothalamic release of GABA as well as an enhanced release of ASP. These results and previous reports suggest that at this stage of sexual maturation, leptin exerts an stimulatory effect on GnRH by inducing release of excitatory amino acids (ASP) and reducing release of inhibitory amino acids (GABA) involved in GnRH control. In prepubertal rats the stimulating effect of the adipocyte hormone on GnRH appears to be related to its stimulative action on GABA which at this age increases GnRH release.
- Published
- 2003
40. Effects of gabaergic and serotoninergic systems on hypothalamic content of catecholamines during sexual development in female rats
- Author
-
Dora, Rondina, Osvaldo J, Ponzo, Berta, Szwarcfarb, Silvia, Carbone, Pablo, Scacchi, and Jaime A, Moguilevsky
- Subjects
Baclofen ,Serotonin ,Muscimol ,Dopamine ,Hypothalamus ,Receptors, GABA-A ,Rats ,Norepinephrine ,Catecholamines ,Receptors, GABA-B ,Animals ,Female ,Sexual Maturation ,Rats, Wistar ,GABA Agonists ,gamma-Aminobutyric Acid - Abstract
The aim of the present investigation was to determine whether the catecholaminergic system is involved in gabaergic and serotoninergic effects on gonadotrophin secretion during sexual development. To this end, we studied the effect of GABAergic and serotoninergic systems on hypothalamic catecholamine content at different stages of sexual development.The effect of GABA A and GABA B agonists and 5-hydroxy-L-tryptophan on hypothalamic noradrenaline and dopamine content were determined in prepubertal (16 days old) and peripubertal (30 days old) rats.At 16 days of age GABA agonists did not modify hypothalamic noradrenaline content, whereas a significant decrease in catecholamine concentration was observed in peripubertal rats at 30 days of age. Similar changes were observed with GABA agonists administration on dopamine hypothalamic levels, i.e no effects at 15 days of age and a significant decrease at 30 days. The administration of 5-hydroxy-l-tryptophan (5-HTP) induced a decrease of hypothalamic concentration of noradrenaline and dopamine at both ages.Results indicate that the GABAergic system modifies the hypothalamic catecholamine content in peripubertal but not in prepubertal rats while serotonin has an inhibitory effect at both stages of sexual maturation. Even though both systems induce similar ontogenic modifications on the gonadotrophin axis (stimulatory effect in prepubertal and inhibitory action in peripubertal and adult rats) the present results appear to indicate that GABAergic and serotoninergic systems regulate gonadotrophin secretion by different hypothalamic mechanisms.
- Published
- 2002
41. Changes in the effect of testosterone on hypothalamic nitric oxide synthetase during sexual maturation. Its relationship with GnRH release
- Author
-
Roxana, Reynoso, Claudia, Mohn, Valeria, Retory, Berta, Szwarcfarb, Silvia, Carbone, Dora, Rondina, and Jaime A, Moguilevsky
- Subjects
Enzyme Activation ,Gonadotropin-Releasing Hormone ,Male ,Animals ,Testosterone ,Sexual Maturation ,Nitric Oxide Synthase ,Gonadal Steroid Hormones ,Nitric Oxide ,Preoptic Area ,Rats - Abstract
To determine the effect of testosterone administration to prepubertal (15 days old) and peripubertal rats (30 days old) on hypothalamic nitric oxide synthetase (NOS), and GnRH release.Hypothalamic samples containing the anterior preoptic and medial basal areas (APO-MBH) were incubated for 30 minutes in 500 l of Earle's medium with glucose (1 mg/ml) and bacitracin (20 mM). GnRH was determined by RIA in the medium and NOS activity was determined in APO-MBH after 10 min of incubation by the conversion of (14) C arginine to (14) C citrulline.Treatment with testosterone propionate, significantly decreased NOS hypothalamic activity in prepubertal male rats. (58.41 +/- 0.85; Testosterone: 25.61 +/- 1.40, p0.001) and had no effect in peripubertal male rats (CONTROL 49.28 +/- 1.50; Testosterone 51.48 +/- 5.2 pmoles NO/10 min/hypothalamus). On the other hand, in prepubertal rats the treatment decreased Gn-RH release (3.62 +/- 0.23; Testosterone: 1.38 +/- 0.11 (pg/ml medium, p0.001) and had no effect on Gn-RH release in 30 days old rats (3.65 +/- 0.33;Testosterone: 4.15 +/- 0.36 pg/ ml, medium).These results clearly demonstrated that testosterone has an inhibitory effect on hypothalamic NOS activity in prepubertal rats while it did not affect the concentration of this neurotransmitter system in peripubertal rats. This pattern is similar to that observed with GnRH hypothalamic release since testosterone has an inhibitory effect in prepubertal rats and did not modify the GnRH release in peripubertal rats. Taking into account the well known stimulatory effect of NO on GnRH and the decrease in the sensitivity of GnRH-gonadotrophin axis to the inhibitory feedback effect of testosterone during sexual maturation and the onset of puberty, it is proposed that the changes here described are connected with maturational modifications in the sexual hormones on-GnRH axis connected with the onset of puberty.
- Published
- 2002
42. Ontogenic modifications in the effect of the GABAergic system on the hypothalamic excitatory amino acids: its relationship with GABAergic control of gonadotrophin secretion during sexual maturation in female rats
- Author
-
Pablo Scacchi, Dora Rondina, Jaime A. Moguilevsky, Berta Szwarcfarb, Roxana Reynoso, Silvia Carbone, and Osvaldo J. Ponzo
- Subjects
medicine.medical_specialty ,Aging ,GABA Agents ,Excitatory Amino Acids ,Hypothalamus ,Glutamic Acid ,Neurotransmission ,Biology ,Synaptic Transmission ,gamma-Aminobutyric acid ,chemistry.chemical_compound ,Developmental Neuroscience ,Internal medicine ,medicine ,Animals ,Sexual Maturation ,gamma-Aminobutyric Acid ,Neurons ,Aspartic Acid ,Glutamate receptor ,Aminooxyacetic Acid ,Luteinizing Hormone ,Aminooxyacetic acid ,Rats ,Endocrinology ,chemistry ,GABAergic ,Female ,Follicle Stimulating Hormone ,Luteinizing hormone ,Gonadotropins ,Developmental Biology ,medicine.drug - Abstract
Aminooxyacetic acid (AOAA), an inhibitor of gamma-aminobutyric transaminase, stimulates the in vitro GABA release by medial and anterior preoptic hypothalamic areas in prepubertal female rats (6, 15 and 30 days of age). This increase of GABA release at 15 days of age, was accompanied by a significant increase (P
- Published
- 2002
43. Effects of aproteic diet on hypothalamic-pituitary- gonadal regulation in the male rat
- Author
-
Osvaldo J., Ponzo, Dora, Rondina, Berta, Szwarcfarb, Silvia, Carbone, Jaime, Moguilevsky, and Pablo, Scacchi
- Abstract
The effect of an aproteic diet (Ap) on the reproductive axis in young male rats was studied. Also the refeeding effect at different times after the aproteic diet was studied. The Ap diet was given during 21 days. In refeeding groups, the control diet was given during 2, 4 and 6 weeks after the aproteic diet. We studied the plasmatic testosterone, luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels. Also the hypothalamic GnRH concentration and in vitro hypothalamic GnRH secretion in basal and induced condition was studied. The total protein deficit produced significant reduction in body, testis, seminal vesicles and prostate weights. This was accompanied with decreased levels of plasmatic testosterone (P0.02). In this aproteic group there was a significant reduction in LH (P0.05) and FSH (P0.05) plasmatic levels. Refeeding with control diet reversed this situation, producing significant increment in LH (P0.05) and FSH levels (P0.01) at the fourth and second weeks, respectively. The basal hypothalamic GnRH secretion did not differ from the control; nevertheless the induced secretion was significantly (P0.05) greater in the aproteic group. Also the hypothalamic GnRH concentration was increased (P0.05) in animals fed with the aproteic diet. The minor testis, prostate, and seminal vesicles" weight, and a decreased plasmatic testosterone in rats fed with an aproteic diet, are produced by a decrease in gonadotrophin secretion. This decrease in turn is caused by a reduction in GnRH secretion, since hypothalamic GnRH concentration is increased in rats fed with the aproteic group, and induced secretion is greater in this group. All these alterations produced by an aproteic diet are reversible, since-with contol diet refeeding-the gonadotrophin secretion returned at control levels.
- Published
- 1998
44. Interactions between GABAergic and serotoninergic systems with excitatory amino acid neurotransmission in the hypothalamic control of gonadotropin secretion in prepubertal female rats
- Author
-
Jaime A. Moguilevsky, Silvia Carbone, Dora Rondina, Wolfgang Wuttke, Pablo Scacchi, and Berta Szwarcfarb
- Subjects
Agonist ,endocrine system ,medicine.medical_specialty ,Serotonin ,medicine.drug_class ,Excitatory Amino Acids ,Hypothalamus ,030209 endocrinology & metabolism ,Pharmacology ,Biology ,Serotonergic ,Bicuculline ,Synaptic Transmission ,5-Hydroxytryptophan ,GABA Antagonists ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Developmental Neuroscience ,Internal medicine ,medicine ,Animals ,Neurotransmitter ,GABA Agonists ,gamma-Aminobutyric Acid ,030304 developmental biology ,0303 health sciences ,Muscimol ,Luteinizing Hormone ,Receptor antagonist ,Gonadotropin secretion ,Rats ,Endocrinology ,nervous system ,chemistry ,GABAergic ,Female ,Dizocilpine Maleate ,Follicle Stimulating Hormone ,Excitatory Amino Acid Antagonists ,hormones, hormone substitutes, and hormone antagonists ,Gonadotropins ,Developmental Biology ,medicine.drug - Abstract
The present studies were designed to study the interrelationships between GABAergic, serotoninergic and excitatory amino acids systems (EAAs) in the control of gonadotropin secretion in prepubertal female rats. For this purpose we determined the effects of N-methyl-d-aspartate (NMDA), an exogenous agonist of EAAs receptors, on LH and FSH secretion in 16-day-old female rats in which the GABA-A and GABA-B receptors were blocked by bicuculline and baclofen or serotonin (5-HT) depleted by p-choloroamphetamine (PCA). In addition the effects of the GABAergic and serotoninergic systems on LH and FSH secretion were evaluated in animals treated with dibenzocycloalkenimine (diocilpine MK-801), an antagonist of NMDA neurotransmission. While muscimol, a GABA- A agonist, induced a significant increase in LH and FSH levels (P
- Published
- 1998
45. Differential effects of the N-methyl-D-aspartate and non-N-methyl-D-aspartate receptors of the excitatory amino acids system on LH and FSH secretion. Its effects on the hypothalamic luteinizing hormone releasing hormone during maturation in male rats
- Author
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Dora Rondina, Jaime A. Moguilevsky, Carlos Feleder, Berta Szwarcfarb, and Silvia Carbone
- Subjects
Male ,endocrine system ,medicine.medical_specialty ,N-Methylaspartate ,medicine.drug_class ,Agonist-antagonist ,Hypothalamus ,Kainate receptor ,Biology ,In Vitro Techniques ,Receptors, N-Methyl-D-Aspartate ,Gonadotropin-Releasing Hormone ,chemistry.chemical_compound ,Internal medicine ,medicine ,Excitatory Amino Acid Agonists ,Animals ,Rats, Wistar ,Molecular Biology ,Testosterone ,Kainic Acid ,General Neuroscience ,Luteinizing Hormone ,Androgen ,Rats ,Endocrinology ,nervous system ,chemistry ,Receptors, Glutamate ,CNQX ,NMDA receptor ,Neurology (clinical) ,Gonadotropin ,Follicle Stimulating Hormone ,Luteinizing hormone ,Developmental Biology - Abstract
The present experiments describe the effect of NMDA and kainate agonists of the NMDA and non-NMDA subtype of receptors respectively of the excitatory amino acids (EAAs) system in prepubertal (16 days of age) and peripubertal (30-day-old rats) male rats on the in vitro hypothalamic release of GnRH, and on the in vivo LH and FSH levels as well as the effect of testosterone on these effects. The addition of NMDA or kainate to the medium containing APOA-MBH areas significantly increased (P < 0.01) the GnRH release as compared with the respective controls. The increase in GnRH release observed with kainate was significantly higher (P < 0.01) than those observed with NMDA. NMDA administration increased significantly (P < 0.01) serum LH levels at both ages of sexual maturation while no effect was observed by kainate administration. MK 801, an antagonist of NMDA neurotransmission, and testosterone abolished the LH release response to NMDA. Contrary to that observed on LH, while NMDA did not modify serum FSH concentrations a significant increase (P < 0.01) was observed with kainate administration in prepubertal and peripubertal rats on this pituitary hormone, and CNQX, an antagonist of non-NMDA neurotransmission, and testosterone administrations blocked this FSH release effect of kainate. The NMDA and kainate release effect on LH and FSH respectively was significantly higher in prepubertal than in peripubertal rats. At both ages NMDA released more LH than kainate FSH. In conclusion, our experiments demonstrated that both subtypes of glutamate receptors NMDA and non-NMDA subtypes of EAAs increased GnRH release by APOA-MBH in vitro during sexual maturation. Nevertheless, while NMDA administration only increased serum LH levels, kainate showed only an effect on increasing FSH concentrations. These differential effects of NMDA and non-NMDA subtypes of EAA receptors on LH and FSH could probably explain some aspects of the differential modifications of LH and FSH observed in different physiological circumstances.
- Published
- 1996
46. Hypothalamic excitatory amino acid system during sexual maturation in female rats
- Author
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Pablo Scacchi, Silvia Carbone, Jaime A. Moguilevsky, Berta Szwarcfarb, and Dora Rondina
- Subjects
Agonist ,medicine.medical_specialty ,N-Methylaspartate ,medicine.drug_class ,Endocrinology, Diabetes and Metabolism ,Excitatory Amino Acids ,Clinical Biochemistry ,Hypothalamus ,Stimulation ,Biology ,Biochemistry ,Gonadotropin-Releasing Hormone ,chemistry.chemical_compound ,Endocrinology ,Internal medicine ,medicine ,Animals ,Sexual Maturation ,Rats, Wistar ,Neurotransmitter ,Molecular Biology ,Progesterone ,Glutamate receptor ,Age Factors ,Estrogens ,Cell Biology ,Gonadotropin secretion ,Rats ,chemistry ,Molecular Medicine ,NMDA receptor ,Female ,Gonadotropin - Abstract
The present results indicate that during sexual maturation the APOA-MBH from rats of 30 days of age released significantly higher quantities of GnRH than the tissue from 16-day-old rats (P < 0.01). The addition of NMDA, an agonist of the excitatory amino acids system (EAAs), to the medium after 30 min of incubation significantly increased (P < 0.01) the GnRH release in normal rats of both ages and this increase was significantly (P < 0.01) higher in 30-day-old rats (to 661%) than in rats of 16 days of age (to 273%). The administration of estrogen-progesterone (EP) to rats of 16 days of age did not modify the GnRH release response to NMDA. On the contrary, at 30 days of age EP administration significantly potentiated the GnRH release response to NMDA since while in the control group NMDA increased the GnRH release to 630%, in the EP-pretreated group this was to around 4700% (P < 0.01). EP pretreatment of prepubertal rats decreases the hypothalamic release of aspartate and glutamate, the excitatory amino acids involved in NMDA neurotransmission and glycine but increases EAAs release in peripubertal rats. On the basis of these results it is proposed that the increase in EAAs release by the hypothalamus is directly connected with the onset of puberty and that the maturation of the positive feedback effect of ovarian hormones on gonadotropin secretion is related to the maturation of the capacity of EP to increase hypothalamic EAAs. Before this maturational event EP inhibits EAAs release as well as gonadotropin release (prepubertal rats). NMDA receptor stimulation leads to a positive mechanism which increases the release of Asp and Glu from APOA-MBH both in prepubertal and peripubertal rats, but EP potentiates this mechanism only in peripubertal rats. This could be an additional neuroendocrine mechanism involved in the increase of gonadotropin during sexual maturation which induces the onset of puberty and the preovulatory discharge of these pituitary hormones.
- Published
- 1995
47. Sexual differences in the effect of the GABAergic system on LH secretion and in the hypothalamic ontogenesis of GABAA receptors in prepubertal rats
- Author
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Jaime A. Moguilevsky, Jorge H. Medina, Silvia Carbone, Miguelina Levi de Stein, and Berta Szwarcfarb
- Subjects
Male ,medicine.medical_specialty ,Aging ,Hypothalamus ,Biology ,gamma-Aminobutyric acid ,chemistry.chemical_compound ,Internal medicine ,medicine ,Sexual maturity ,Animals ,Sexual Maturation ,Rats, Wistar ,Molecular Biology ,gamma-Aminobutyric Acid ,Sex Characteristics ,GABAA receptor ,Muscimol ,General Neuroscience ,Aminooxyacetic Acid ,Luteinizing Hormone ,Receptors, GABA-A ,Aminooxyacetic acid ,Rats ,Endocrinology ,chemistry ,Organ Specificity ,GABAergic ,Female ,Neurology (clinical) ,Luteinizing hormone ,Orchiectomy ,Developmental Biology ,medicine.drug - Abstract
The administration of aminooxyacetic acid (AOAA), which increases hypothalamic GABA concentrations, induced a significant increase in LH levels in female rats of 12, 16 and 18 days of age. This stimulatory effect of AOAA on serum LH levels was not observed at 21 and 25 days of age whereas a significant decrease in the LH concentrations by AOAA was found at 30 days of age. The neonatal androgenization of female rats abolished the effects of AOAA and no effects of AOAA were found in male rats at the different ages studied. The muscimol binding sites in medial basal and preoptic anterior hypothalamic areas showed a significant different sexual ontogenic pattern. Males rats castrated at birth showed a very similar ontogenic pattern of [3H]muscimol binding sites to female rats and significantly different to male control rats. It is concluded that there are sexual differences in the effect of GABAergic system on LHRH-LH secretion and in the development of hypothalamic GABAA receptors during sexual maturation. These differences are probably connected with the neonatal exposure to androgens that would induced changes in the composition and probably in the properties of GABAA receptor that in turn modified its effects on LHRH neurons.
- Published
- 1994
48. Amino acid levels in the hypothalamus and response to N-methyl-D-aspartate and/or dizocilpine administration during sexual maturation in female rats
- Author
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Jaime A. Moguilevsky, M. E. Otero Losada, Berta Szwarcfarb, and Silvia Carbone
- Subjects
endocrine system ,medicine.medical_specialty ,N-Methylaspartate ,Endocrinology, Diabetes and Metabolism ,Injections, Subcutaneous ,Central nervous system ,Hypothalamus ,Biology ,Cellular and Molecular Neuroscience ,Basal (phylogenetics) ,Endocrinology ,Internal medicine ,medicine ,Sexual maturity ,Animals ,Sexual Maturation ,Amino Acids ,Rats, Wistar ,chemistry.chemical_classification ,Sex Characteristics ,Endocrine and Autonomic Systems ,Osmolar Concentration ,Amino acid ,Rats ,Dizocilpine ,Preoptic area ,medicine.anatomical_structure ,nervous system ,chemistry ,NMDA receptor ,Female ,Dizocilpine Maleate ,hormones, hormone substitutes, and hormone antagonists ,medicine.drug - Abstract
Amino acid concentration in the anterior preoptic area and medial basal hypothalamus was determined by HPLC in female rats: (1) at 16 (prepubertal) vs. 30 (peripubertal) days of age and (2) after N-methyl-D-aspartate (NMDA) or dizocilpine (MK-801) administration in both groups. 30-day-old rats had higher levels of aspartate (Asp; 24%), glutamate (Glu; 49%) and glycine (Gly; 44%) and lower levels of taurine (Tau; 43%) than 16-day-old rats. In 16-day-old rats, NMDA (30 mg/kg, s.c., 10 min) increased the Glut concentration (48%). This effect was prevented by MK-801 pretreatment (1 mg/kg, s.c., 1 h), which did not modify amino acid concentrations per se. In 30-day-old rats, NMDA treatment increased Glut (24%) and asp (42%) levels. MK-801 pretreatment abolished NMDA-induced changes and reduced Tau (26%) and Gly (30%) levels. MK-801 administration alone reduced the concentration of Glut (39%), Asp (54%), Tau (33%) and Gly (31%). It is concluded that both (1) the concentration of Asp, Glu, Gly and Tau and (2) the changes induced by NMDA receptor activation or blockade are different at 16 vs. 30 days of age. The existence of a tonic (positive) control on amino acid levels linked to the NMDA receptor which would be immature or absent at 16 days of age is suggested.
- Published
- 1993
49. Sexual maturation modifies the catecholaminergic control of gonadotrophin secretion and the effect of ovarian hormones on hypothalamic neurotransmitters in female rats
- Author
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Jaime A. Moguilevsky, Pablo Arias, Silvia Carbone, Berta Szwarcfarb, and Dora Rondina
- Subjects
medicine.medical_specialty ,Aging ,Serotonin ,Tyrosine 3-Monooxygenase ,Endocrinology, Diabetes and Metabolism ,Dopamine ,Hypothalamus ,Methyltyrosines ,Biology ,Cellular and Molecular Neuroscience ,Follicle-stimulating hormone ,Norepinephrine ,Endocrinology ,Catecholamines ,Internal medicine ,medicine ,Animals ,Sexual Maturation ,Progesterone ,Catecholaminergic ,Neurotransmitter Agents ,Tyrosine hydroxylase ,Estradiol ,Endocrine and Autonomic Systems ,Rats, Inbred Strains ,Hydroxyindoleacetic Acid ,Luteinizing Hormone ,Rats ,Kinetics ,alpha-Methyltyrosine ,Catecholamine ,Alpha-Methyltyrosine ,Female ,Follicle Stimulating Hormone ,Luteinizing hormone ,medicine.drug - Abstract
alpha-Methyl-p-tyrosine (alpha-MT), a competitive inhibitor of tyrosine hydroxylase, was used to block the synthesis of hypothalamic catecholamines in immature female rats of 14, 16 and 30 days of age and in castrated adults. The administration of alpha-MT (300 mg/kg body weight, free base) induced a significant decay in the hypothalamic content of norepinephrine (NE) and dopamine (DA) within the first 120 min. A second dose (150 mg/kg body weight), given 2 h after the first injection, did not further modify the low catecholamine levels observed 120 min after the first alpha-MT administration. The administration of 300 mg/kg body weight of alpha-MT induced a significant increase in LH concentrations in rats aged 14 and 16 days. On the contrary, after an alpha-MT injection, a significant LH decrease was observed in 30-day-old and in adult castrated rats. alpha-MT also increased FSH levels in prepubertal rats of 16 days of age, but no change occurred in 30-day-old and in adult rats. The administration of estrogen-progesterone (EP) to prepubertal rats of 16 days of age induced a significant decrease in serum LH levels as well as in the serotonin (5-HT) and 5-hydroxyindole-acetic acid (5-HIAA) concentrations in the anterior-preoptic hypothalamic area (AH-POA), but not in the medial basal hypothalamus. No modifications in the catecholamine content of these hypothalamic areas were observed in this age group after EP administration. On the contrary, in 30-day-old rats, EP induced a significant LH release as well as an increase in AH-POA concentrations of 5-HT, 5-HIAA and catecholamines.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1990
50. Bupropion. Effects on cerebral monoamines in rat and on blood pressure in dog
- Author
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Irma O. Mastronardi, Vicente H. Cicardo, Dora Rondina, and Silvia Carbone
- Subjects
Male ,Biogenic Amines ,Femoral vein ,Blood Pressure ,Motor Activity ,Dogs ,Species Specificity ,mental disorders ,Heart rate ,medicine ,Animals ,Bupropion ,gamma-Aminobutyric Acid ,Pharmacology ,Propiophenones ,Glutamate Decarboxylase ,business.industry ,Brain ,Electric Stimulation ,Rats ,Monoamine neurotransmitter ,Blood pressure ,4-Aminobutyrate Transaminase ,Anesthesia ,business ,medicine.drug - Abstract
1. 1. Intravenous injections of bupropion into the femoral vein of dogs did not change cardiovascular peripheric responses because it did not affect significantly either arterial pressure or heart rate. 2. 2. In acute experiments bupropion increased the levels of DA, NA and 5-HT in the brain of rats. 3. 3. There was a remarkable correlation between the levels of monoamines and the hypermotility.
- Published
- 1986
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