14 results on '"R. Torpia"'
Search Results
2. Factors of Progression in IgA Mesangial Nephropathy
- Author
-
A. Ragni, G. D’Amico, and R. Torpia
- Subjects
Text mining ,business.industry ,Immunology ,medicine ,medicine.disease ,business ,Nephropathy - Published
- 2015
- Full Text
- View/download PDF
3. [Acute renal failure after videolaparoscopic surgery: an avoidable complication?]
- Author
-
P M, Allaria, A, Lucatello, C, Battaglia, E, Gandini, I, D'Amato, I, Brambilla P Soni, A, Castiglioni, F, Caligara, R, Torpia, A, Molinari, and A, Giangrande
- Subjects
Adult ,Ovarian Neoplasms ,Adolescent ,Remission, Spontaneous ,Video-Assisted Surgery ,Acute Kidney Injury ,Ovarian Cysts ,Treatment Outcome ,Risk Factors ,Pneumoperitoneum ,Fluid Therapy ,Humans ,Female ,Laparoscopy - Abstract
Videolaparoscopic surgery exposes the abdominal organs to the mechanical effect of pneumoperitoneum at pressure values between 12 and 15 mm Hg, which are considered safe. Nevertheless, experimental data have shown that this pressure range can represent a hemodynamic risk factor as it may induce a decrease in the venous return to the right ventricle, a decrease in cardiac output, and activation of the sympathetic nervous system and renin angiotensin system. We report two cases of acute renal failure that occurred soon after videolaparoscopy in young female patients without any evidence of ongoing renal disease. Patient A was 29 years old and was submitted to videolaparoscopic surgery in a follow-up program after surgical treatment of ovarian cancer; patient B was 15 years old and was submitted to the surgical removal of a monolateral ovarian cyst. In neither of the cases was it necessary to perform hemodialysis. Patient A underwent a renal biopsy under ultrasound guidance; optic microscopy showed only in ra- and extraglomerular capillary congestion. In both cases the acute renal failure resolved completely and the patients where discharged with normal renal function. Taking in to account that normal renal venous pressure levels are around 4 mmHg we think that a) a 15 mmHg pneumoperitoneum may represent a risk factor during videolaparoscopic surgery mainly if the patient's extracellular volume is not properly expanded; b) administration of nonsteroidal anti-inflammatory drugs in order to prevent surgical pain may inhibit vasodilatory prostaglandin availability; c) onset of oliguria during the surgical procedure suggests that extracellular volume expansion is required.
- Published
- 2007
4. Prevalence of hyperlipidemia in a cohort of CAPD patients. Italian Cooperative Peritoneal Dialysis Study Group (ICPDSG)
- Author
-
R, Cocchi, G, Viglino, G, Cancarini, L, Catizone, A, Favazza, A, Tommasi, M, Salomone, G P, Segoloni, R, Torpia, and A, Giangrande
- Subjects
Blood Glucose ,Male ,Sex Characteristics ,Time Factors ,Hypercholesterolemia ,Hyperlipidemias ,Middle Aged ,Cohort Studies ,Cholesterol ,Peritoneal Dialysis, Continuous Ambulatory ,Reference Values ,Prevalence ,Humans ,Regression Analysis ,Female ,Kidney Diseases ,Lipoproteins, HDL ,Serum Albumin ,Triglycerides - Abstract
An association between hyperlipidemia and cardiovascular disease is well described in the literature. We conducted an observational study in order to evaluate the lipid profile, the prevalence of hyperlipidemia and its relationship with age, sex, duration of CAPD, peritoneal glucose load (PGL), serum albumin (ALB), serum glucose (GLU), and BMI in a large cohort of uremics undergoing long-term treatment with CAPD. 457 nondiabetic patients (245 males, 212 females; mean age 63.8 +/- 11.9 years; mean duration of CAPD: 41.8 +/- 26.9 months) treated during 1992 in 25 centers participating in the Italian Cooperative Peritoneal Dialysis Study Group (ICPDSG) were studied. The serum lipid parameters evaluated were triglycerides (TG), total cholesterol (CHO), HDL-cholesterol (HDL). Indications given in the New England Journal of Medicine, SI Unit Conversion Guide, 1992, were adopted for normal ranges. In the whole population the evaluation of lipid parameters showed: TG 227.4 +/- 123.3 mg/dl, CHO 232.8 +/- 56.0 mg/dl, HDL 40.7 +/- 12.0 mg/dl. No differences were found between the two sexes with regard to age, BMI, duration of CAPD, distribution of renal diseases, TG, ALB, and GLU; whereas CHO and HDL were significantly lower in males than in females (CHO: 222.2 +/- 53.5 vs. 245.0 +/- 56.5 mg/dl, p0.001; HDL: 39.3 +/- 11.4 vs. 42.6 +/- 12.6 mg/dl, p0.05). The prevalence of hypercholesterolemia was significantly lower in males than in females (19.7 vs. 35.4%; p0.001). The multiple regression analysis indicated that TG were directly correlated to PGL (p0.05), and HDL was inversely correlated with TG (p0.001). The coexistence of the two variables (TG and HDL) may increase the risk of cardiovascular events. Further strategies should therefore be developed to select and manage CAPD patients to reduce the incidence of hyperlipidemia.
- Published
- 1996
5. Low doses of drugs able to alter intestinal mucosal permeability to food antigens (5-aminosalicylic acid and sodium cromoglycate) do not reduce proteinuria in patients with IgA nephropathy: A preliminary noncontrolled trial
- Author
-
C. Petrini, C. Bazzi, Girolamo Arrigo, Giuseppe D'Amico, V. Rizza, R.A. Sinico, A. Ragni, R. Torpia, Bazzi, C, Sinico, R, Petrini, C, Rizza, V, Torpia, R, Arrigo, G, Ragni, A, and D'Amico, G
- Subjects
Adult ,Male ,medicine.medical_specialty ,Aminosalicylic acid ,urologic and male genital diseases ,Gastroenterology ,Permeability ,Nephropathy ,chemistry.chemical_compound ,Intestinal mucosa ,Internal medicine ,Immunopathology ,Cromolyn Sodium ,medicine ,Humans ,Antigens ,Intestinal Mucosa ,Mesalamine ,Creatinine ,Proteinuria ,business.industry ,Glomerulonephritis ,Glomerulonephritis, IGA ,Middle Aged ,medicine.disease ,Ulcerative colitis ,Aminosalicylic Acid ,Aminosalicylic Acids ,Endocrinology ,chemistry ,Food ,Antigen ,Female ,medicine.symptom ,business ,Human - Abstract
In an uncontrolled trial, patients with IgA nephropathy (IgAN) were treated with drugs that can alter the intestinal mucosal permeability to food antigens. These drugs are known to ameliorate urinary abnormalities and histological lesions of IgAN associated with ulcerative colitis or Crohn's disease [5-aminosalicylic acid (5-ASA)] or to prevent, in mice, the induction of IgAN-like disease by oral immunization [disodium cromoglycate (SCG)]. Nine patients [serum creatinine (s-Cr) less than 2 mg/dl; 24-hour proteinuria higher than 1.5 g, but not nephrotic) were treated with 5-ASA (2.4 g/day for 6 months); 9 similar patients were treated with SCG (400 mg/day for 6 months); the follow-up extended to 6 months after stopping therapy. The 5-ASA group showed a slight but not significant decrease in s-Cr, 24-hour/proteinuria, IgA circulating immune complexes (IgA-CIC) and IgA rheumatoid factor (IgA-RF); serum beta 2-microglobulin and serum IgA were unchanged; 2 of 9 treated patients showed, after 6 months of therapy, a reduction in proteinuria of more than 50% that lasted for the subsequent 18 months. The SCG-treated group showed a slight but not significant increase in 24-hour proteinuria and a significant decrease in serum IgA; unchanged were s-Cr, IgA-CIC, IgA-RF, serum beta 2-microglobulin; no patient treated with SCG showed a reduction in proteinuria of more than 50%. At the dosages and for the periods used, 5-ASA and SCG did not show a significant influence on clinical and laboratory parameters of disease in IgAN; other trials with increased dosages are warranted to definitely ascertain the possible therapeutic role of these drugs in IgAN.
- Published
- 1992
6. Persistence of a defective tuberoinfundibular dopaminergic function in rats after long-term removal of oestrogen treatment. An in vivo study
- Author
-
Daniela Cocchi, Giovanni L. Rossi, R. Torpia, E. E. Müller, and A. Pen̄alva
- Subjects
Adenoma ,Agonist ,endocrine system ,medicine.medical_specialty ,Nomifensine ,Time Factors ,medicine.drug_class ,Endocrinology, Diabetes and Metabolism ,Hypothalamus ,Stimulation ,Receptors, Dopamine ,dopaminergic system ,estrogens ,Endocrinology ,In vivo ,Internal medicine ,D-Ala(2),MePhe(4),Met(0)-ol-enkephalin ,medicine ,Animals ,Pituitary Neoplasms ,Neurons ,Estradiol ,Chemistry ,Dopaminergic ,Rats, Inbred Strains ,General Medicine ,Receptor antagonist ,Domperidone ,Prolactin ,Rats ,Female ,medicine.drug - Abstract
The function of the tuberoinfundibular dopaminergic (TIDA) neurons of 49 rats bearing oestradiolvalerate (EV)-induced prolactin (Prl) secreting tumours (prolactinomas) was evaluated in vivo, 7 months after discontinuation of EV-treatment, with neuroactive drugs acting via stimulation or inhibition of DA neurotransmission. Based on the size and morphologic appearance of the pituitary and on determination of plasma Prl levels, rats previously treated with EV could be divided into those bearing macro- (31/49) and those bearing microprolactinomas (18/49). Administration of the indirect DA agonist drug nomifensine (10 mg/kg iv) lowered plasma Prl levels in control rats, but failed to do so in rats bearing either macro- or microprolactinomas. Administration of the DA receptor antagonist domperidone (50 μg/kg ip) or the synthetic enkephalin analogue FK 33-824 (1 mg/kg ip) failed to induce a rise in plasma Prl in rats with macro-, but induced a clear-cut rise in plasma Prl in those with microprolactinomas. Prl unresponsiveness to all three neuroactive drugs indicates that long time after EV withdrawal TIDA neuronal function is still highly impaired in rats bearing EVinduced macroprolactinomas. The impairment of TIDA neuronal function would be of lesser extent in rats bearing microprolactinomas as revealed by a defective response to only one of the three applied neuroendocrine probes.
- Published
- 1985
- Full Text
- View/download PDF
7. Factors of progression in IgA mesangial nephropathy
- Author
-
G, D'Amico, A, Ragni, and R, Torpia
- Subjects
Humans ,Glomerulonephritis, IGA ,Prognosis ,Glomerular Mesangium ,Hematuria - Published
- 1989
8. Prolactin releasing and luteinizing hormone inhibiting activity of dermorphin shorter homologues in the rat
- Author
-
E. C. Degli Uberti, S. Salvadori, Giorgio Trasforini, Daniela Cocchi, R. Perelli-Cippo, Roberto Tomatis, and R. Torpia
- Subjects
medicine.medical_specialty ,prolactin ,Radioimmunoassay ,Context (language use) ,Peptide hormone ,Pentapeptide repeat ,General Biochemistry, Genetics and Molecular Biology ,Structure-Activity Relationship ,chemistry.chemical_compound ,Internal medicine ,medicine ,Animals ,opioid peptides ,gonadotropins ,Castration ,General Pharmacology, Toxicology and Pharmaceutics ,Opioid peptide ,Injections, Intraventricular ,Analgesics ,Behavior, Animal ,Tetrapeptide ,Naloxone ,Chemistry ,General Medicine ,Dermorphin ,Luteinizing Hormone ,Prolactin ,Rats ,Endocrinology ,Female ,Anura ,Luteinizing hormone ,Oligopeptides ,hormones, hormone substitutes, and hormone antagonists - Abstract
Dermorphin, a heptapeptide isolated from the skin of the frogs Phillomedusa sauvagei and Phillomedusa rhodei, is endowed with potent peripheral and central opioid-like activity. Intracerebroventricular (icv) injection of dermorphin (31.2, 62.5 and 125 pmol/100g) induced in ovariectomized (OVX) rats dose related rises and decreases in prolactin (PRL) and luteinizing hormone (LH) levels, respectively. The aim of this work was to evaluate the same endocrine responses after administration of shorter peptide amide homologues, related to the N-terminal sequence of dermorphin. These compounds retain a substantial analgesic activity although the latter decreases with the decrease in the number of amino acid residues. Icv administration of the hexapeptide homologue (dermorphin 1-6 amide) to OVX rats did not induce any PRL rise or LH inhibition, even at the high dose of 250 pmol/100g. The pentapeptide (dermorphin 1-5 amide), instead, increased PRL and decreased LH secretion, although the effect was significant only at the dose of 250 pmol/100g. Administration of the tetrapeptide (dermorphin 1-4 amide) induced a significant PRL rise and LH inhibition at both the doses of 125 and 250 pmol/100g. The tetrapeptide was the smallest fragment of the dermorphin moiety which caused endocrine responses while the tripeptide (dermorphin 1-3 amide) was completely ineffective in this context. These data indicate that a complete dissociation exists between the behavioral and endocrine effects of the dermorphin homologues examined. In fact, shorter dermorphins whose analgesic potency was directly related to the number of amino acids, exhibited an opposite pattern in evoking endocrine effects.
- Published
- 1985
9. [Strongyloidiasis in nephrologic patients].
- Author
-
Gravellone L, Battaglia C, Caligara F, D'Amato I, Gandini E, Lucatello A, Rizzo MA, Torpia R, Brigante G, and Castiglioni A
- Subjects
- Adult, Antinematodal Agents therapeutic use, Humans, Ivermectin therapeutic use, Male, Middle Aged, Strongyloidiasis drug therapy, Kidney Diseases complications, Strongyloidiasis complications
- Abstract
Strongyloides stercoralis is a nematode causing strongyloidiasis, more frequent in immigrants and in travelers coming from tropical and subtropical areas. Infection is usually asymptomatic, frequently associated with eosinophilia. Immunocompromised patients are at high risk of developing hyperinfection syndrome (HI) or dissemination (SD), life threatening complications. Diagnosis of strongyloidiasis is firstly based on larvae isolation in stool samples; specific therapy involves the use of ivermectin as first choice and albendazole as second choice. We describe two cases of strongyloidiasis. The first one is a disseminated strongyloidiasis occurred in an Ecuadorian male on corticosteroid therapy for nephrotic syndrome due to focal segmental glomerulosclerosis, successfully treated with ivermectin; the second one involves another Ecuadorian male affected by acute kidney failure and nephrotic syndrome in IgA nephropathy with a diagnosis of chronic strongyloidiasis performed before starting the immunosuppressive treatment. The timing of treatment with ivermectin has allowed the complete eradication of the parasite before starting steroid and mycophenolate mofetil therapy, preventing the occurrence of a disseminated infection. Epidemiological data show us how strongyloidiasis is rising at our latitude because of increased number of migrants and travelers coming from endemic areas. So we must always exclude asymptomatic strongyloidiasis before prescribing a steroid or immunosuppressive therapy, in order to avoid developement of disseminated and often fatal disease.
- Published
- 2015
10. [Acute renal failure after videolaparoscopic surgery: an avoidable complication?].
- Author
-
Allaria PM, Lucatello A, Battaglia C, Gandini E, D'Amato I, Brambilla P Soni I, Castiglioni A, Caligara F, Torpia R, Molinari A, and Giangrande A
- Subjects
- Acute Kidney Injury therapy, Adolescent, Adult, Female, Fluid Therapy methods, Humans, Ovarian Cysts surgery, Ovarian Neoplasms surgery, Pneumoperitoneum complications, Remission, Spontaneous, Risk Factors, Treatment Outcome, Acute Kidney Injury etiology, Laparoscopy adverse effects, Video-Assisted Surgery adverse effects
- Abstract
Videolaparoscopic surgery exposes the abdominal organs to the mechanical effect of pneumoperitoneum at pressure values between 12 and 15 mm Hg, which are considered safe. Nevertheless, experimental data have shown that this pressure range can represent a hemodynamic risk factor as it may induce a decrease in the venous return to the right ventricle, a decrease in cardiac output, and activation of the sympathetic nervous system and renin angiotensin system. We report two cases of acute renal failure that occurred soon after videolaparoscopy in young female patients without any evidence of ongoing renal disease. Patient A was 29 years old and was submitted to videolaparoscopic surgery in a follow-up program after surgical treatment of ovarian cancer; patient B was 15 years old and was submitted to the surgical removal of a monolateral ovarian cyst. In neither of the cases was it necessary to perform hemodialysis. Patient A underwent a renal biopsy under ultrasound guidance; optic microscopy showed only in ra- and extraglomerular capillary congestion. In both cases the acute renal failure resolved completely and the patients where discharged with normal renal function. Taking in to account that normal renal venous pressure levels are around 4 mmHg we think that a) a 15 mmHg pneumoperitoneum may represent a risk factor during videolaparoscopic surgery mainly if the patient's extracellular volume is not properly expanded; b) administration of nonsteroidal anti-inflammatory drugs in order to prevent surgical pain may inhibit vasodilatory prostaglandin availability; c) onset of oliguria during the surgical procedure suggests that extracellular volume expansion is required.
- Published
- 2007
11. Prevalence of hyperlipidemia in a cohort of CAPD patients. Italian Cooperative Peritoneal Dialysis Study Group (ICPDSG).
- Author
-
Cocchi R, Viglino G, Cancarini G, Catizone L, Favazza A, Tommasi A, Salomone M, Segoloni GP, Torpia R, and Giangrande A
- Subjects
- Blood Glucose metabolism, Cholesterol blood, Cohort Studies, Female, Humans, Hypercholesterolemia blood, Hyperlipidemias blood, Kidney Diseases blood, Kidney Diseases therapy, Lipoproteins, HDL blood, Male, Middle Aged, Prevalence, Reference Values, Regression Analysis, Serum Albumin analysis, Sex Characteristics, Time Factors, Triglycerides blood, Hypercholesterolemia epidemiology, Hyperlipidemias epidemiology, Peritoneal Dialysis, Continuous Ambulatory
- Abstract
An association between hyperlipidemia and cardiovascular disease is well described in the literature. We conducted an observational study in order to evaluate the lipid profile, the prevalence of hyperlipidemia and its relationship with age, sex, duration of CAPD, peritoneal glucose load (PGL), serum albumin (ALB), serum glucose (GLU), and BMI in a large cohort of uremics undergoing long-term treatment with CAPD. 457 nondiabetic patients (245 males, 212 females; mean age 63.8 +/- 11.9 years; mean duration of CAPD: 41.8 +/- 26.9 months) treated during 1992 in 25 centers participating in the Italian Cooperative Peritoneal Dialysis Study Group (ICPDSG) were studied. The serum lipid parameters evaluated were triglycerides (TG), total cholesterol (CHO), HDL-cholesterol (HDL). Indications given in the New England Journal of Medicine, SI Unit Conversion Guide, 1992, were adopted for normal ranges. In the whole population the evaluation of lipid parameters showed: TG 227.4 +/- 123.3 mg/dl, CHO 232.8 +/- 56.0 mg/dl, HDL 40.7 +/- 12.0 mg/dl. No differences were found between the two sexes with regard to age, BMI, duration of CAPD, distribution of renal diseases, TG, ALB, and GLU; whereas CHO and HDL were significantly lower in males than in females (CHO: 222.2 +/- 53.5 vs. 245.0 +/- 56.5 mg/dl, p < 0.001; HDL: 39.3 +/- 11.4 vs. 42.6 +/- 12.6 mg/dl, p < 0.05). The prevalence of hypercholesterolemia was significantly lower in males than in females (19.7 vs. 35.4%; p < 0.001). The multiple regression analysis indicated that TG were directly correlated to PGL (p < 0.05), and HDL was inversely correlated with TG (p < 0.001). The coexistence of the two variables (TG and HDL) may increase the risk of cardiovascular events. Further strategies should therefore be developed to select and manage CAPD patients to reduce the incidence of hyperlipidemia.
- Published
- 1996
12. Ultrastructure analysis of Tenckhoff chronic peritoneal catheters used in continuous ambulatory peritoneal dialysis patients.
- Author
-
Giangrande A, Allaria P, Torpia R, Baldassari L, Gelosia A, and Donelli G
- Subjects
- Bacteria growth & development, Equipment Contamination, Female, Humans, Male, Microscopy, Electron, Scanning, Middle Aged, Surface Properties, Catheters, Indwelling, Peritoneal Dialysis, Continuous Ambulatory instrumentation
- Abstract
The luminal and external surfaces of 18 curled silicone double-cuff catheters removed from patients who had been on continuous ambulatory peritoneal dialysis (CAPD) for 2-77 months (average 37 +/- 21 months) were analyzed by scanning electron microscopy (SEM) and microbiological cultures. Eight catheters (G1) were removed due to recurrent peritonitis or peritonitis refractory to antibiotic management, and the others (G2) due to local or clinical problems. The peritonitis rate was one episode every 24 patient-months in G1, and 80 patient-months in G2. All catheter surfaces were covered with proteinlike granular deposits (0.15 +/- 0.11/cm); 6 catheters were covered by microbial biofilm (0.24 +/- 0.16/cm). Positive cultures of catheter segments were obtained in 6 cases (4 for G1 and 2 for G2) with a preponderance (33%) of Staphylococcus aureus among the cultivated bacteria. Structural defects and small linear tears were present on both luminal and external surfaces in 8 catheters. Structural defects were frequent in the catheters removed for recurrent peritonitis. Linear tears appeared more frequently in the catheters used for a longer time. Structural defects of catheter surfaces were also discovered in the newer devices. The structural defects of the catheter appear to facilitate microbial adhesion and colonization and to predispose the patient to recurrence of peritonitis. A better catheter design and an improvement in the production process should therefore be recommended.
- Published
- 1993
13. Low doses of drugs able to alter intestinal mucosal permeability to food antigens (5-aminosalicylic acid and sodium cromoglycate) do not reduce proteinuria in patients with IgA nephropathy: a preliminary noncontrolled trial.
- Author
-
Bazzi C, Sinico RA, Petrini C, Rizza V, Torpia R, Arrigo G, Ragni A, and D'Amico G
- Subjects
- Adult, Antigens metabolism, Female, Food, Glomerulonephritis, IGA urine, Humans, Intestinal Mucosa drug effects, Intestinal Mucosa immunology, Male, Mesalamine, Middle Aged, Permeability drug effects, Proteinuria drug therapy, Proteinuria urine, Aminosalicylic Acids pharmacology, Cromolyn Sodium pharmacology, Glomerulonephritis, IGA drug therapy
- Abstract
In an uncontrolled trial, patients with IgA nephropathy (IgAN) were treated with drugs that can alter the intestinal mucosal permeability to food antigens. These drugs are known to ameliorate urinary abnormalities and histological lesions of IgAN associated with ulcerative colitis or Crohn's disease [5-aminosalicylic acid (5-ASA)] or to prevent, in mice, the induction of IgAN-like disease by oral immunization [disodium cromoglycate (SCG)]. Nine patients [serum creatinine (s-Cr) less than 2 mg/dl; 24-hour proteinuria higher than 1.5 g, but not nephrotic) were treated with 5-ASA (2.4 g/day for 6 months); 9 similar patients were treated with SCG (400 mg/day for 6 months); the follow-up extended to 6 months after stopping therapy. The 5-ASA group showed a slight but not significant decrease in s-Cr, 24-hour/proteinuria, IgA circulating immune complexes (IgA-CIC) and IgA rheumatoid factor (IgA-RF); serum beta 2-microglobulin and serum IgA were unchanged; 2 of 9 treated patients showed, after 6 months of therapy, a reduction in proteinuria of more than 50% that lasted for the subsequent 18 months. The SCG-treated group showed a slight but not significant increase in 24-hour proteinuria and a significant decrease in serum IgA; unchanged were s-Cr, IgA-CIC, IgA-RF, serum beta 2-microglobulin; no patient treated with SCG showed a reduction in proteinuria of more than 50%. At the dosages and for the periods used, 5-ASA and SCG did not show a significant influence on clinical and laboratory parameters of disease in IgAN; other trials with increased dosages are warranted to definitely ascertain the possible therapeutic role of these drugs in IgAN.
- Published
- 1992
- Full Text
- View/download PDF
14. Prolactin releasing and luteinizing hormone inhibiting activity of dermorphin shorter homologues in the rat.
- Author
-
Cocchi D, Degli Uberti EC, Trasforini G, Salvadori S, Tomatis R, Torpia R, and Perelli-Cippo R
- Subjects
- Analgesics, Animals, Anura, Behavior, Animal drug effects, Castration, Female, Injections, Intraventricular, Luteinizing Hormone blood, Naloxone pharmacology, Oligopeptides antagonists & inhibitors, Opioid Peptides, Prolactin blood, Radioimmunoassay, Rats, Structure-Activity Relationship, Luteinizing Hormone metabolism, Oligopeptides pharmacology, Prolactin metabolism
- Abstract
Dermorphin, a heptapeptide isolated from the skin of the frogs Phillomedusa sauvagei and Phillomedusa rhodei, is endowed with potent peripheral and central opioid-like activity. Intracerebroventricular (icv) injection of dermorphin (31.2, 62.5 and 125 pmol/100g) induced in ovariectomized (OVX) rats dose related rises and decreases in prolactin (PRL) and luteinizing hormone (LH) levels, respectively. The aim of this work was to evaluate the same endocrine responses after administration of shorter peptide amide homologues, related to the N-terminal sequence of dermorphin. These compounds retain a substantial analgesic activity although the latter decreases with the decrease in the number of amino acid residues. Icv administration of the hexapeptide homologue (dermorphin 1-6 amide) to OVX rats did not induce any PRL rise or LH inhibition, even at the high dose of 250 pmol/100g. The pentapeptide (dermorphin 1-5 amide), instead, increased PRL and decreased LH secretion, although the effect was significant only at the dose of 250 pmol/100g. Administration of the tetrapeptide (dermorphin 1-4 amide) induced a significant PRL rise and LH inhibition at both the doses of 125 and 250 pmol/100g. The tetrapeptide was the smallest fragment of the dermorphin moiety which caused endocrine responses while the tripeptide (dermorphin 1-3 amide) was completely ineffective in this context. These data indicate that a complete dissociation exists between the behavioral and endocrine effects of the dermorphin homologues examined. In fact, shorter dermorphins whose analgesic potency was directly related to the number of amino acids, exhibited an opposite pattern in evoking endocrine effects.
- Published
- 1985
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.