Search

INTRODUÇÃO: O Stand Up Paddle (SUP) ou Hoe He’e Nalu, em havaiano, é um esporte que consiste basicamenteem remar de pé sobre uma prancha. Surgiu no Havaí, por volta de 1960, por surfistas, usavam grande pranchas e remavam nelas, para tirar fotos dos alunos e aspirantes do Surf da época. Mesmo sendo umesporte antigo entrou em evidência há poucos anos, tem como objetivo realizar uma revisão da literatura sobre aspectos atuais e relevantes deste esporte. MATERIAIS E MÉTODOS: Para este trabalho, foi realizada uma pesquisa na base de dados PubMed, em maio de 2018, utilizando como palavra-chave Stand Up Paddle. RESULTADOS: Foram encontrados 09 artigos sobre este tema, sendo todos originais. Dos artigos encontrados: 02 abordavam sobre lesão de praticantes do esporte, 02 artigos tratavam sobre a fisiologia do exercício, com praticantes e atletas de SUP, sobre postura, foram encontrados mais 02 artigos, também foram encontrados 02 artigos que abordavam a composição corporal e apenas 01 artigo, que não é relacionado ao esporte SUP,mas apareceu na pesquisa do banco de dados, bem provavelmente por apresentar a palavra “stand” e “paddle”. CONCLUSÃO: Conclui-se com esse trabalho que existem poucas pesquisas sobre o esporte SUP, cadastradas no banco de dados do Pubmed, mostrando a necessidade de mais estudos sobre as diversas áreas da saúde, para conhecer e compreender a fisiologia, a biomecânica, as lesões e dentre outros desse esporte. Se comparado esse esporte com outros esportes de remo, o SUP é o único que é praticado em pé.

BACKGROUND Kinesiotherapy is an option to mitigate worsening neuropsychomotor function due to human aging. Moreover, exergames are beneficial for the practice of physical therapy by older patients. Physical exercise interventions are known to alter the epigenome, but little is known about their association with exergames. OBJECTIVE We aim to evaluate the effects of kinesiotherapy with exergaming on older women’s epigenetic marks and cognitive ability, as well as on their clinical functional variables. Our hypothesis states that this kind of therapy can elicit equal or even better outcomes than conventional therapy. METHODS We will develop a virtual clinic exergame with 8 types of kinesiotherapy exercises. Afterward, we will conduct a 1:1 randomized clinical trial to compare the practice of kinesiotherapy with exergames (intervention group) against conventional kinesiotherapy (control group). A total of 24 older women will be enrolled for 1-hour sessions performed twice a week, for 6 weeks, totaling 12 sessions. We will assess outcomes using epigenetic blood tests, the Montreal Cognitive Assessment test, the Timed Up and Go test, muscle strength grading in a hydraulic dynamometer, and the Game Experience Questionnaire at various stages. RESULTS The project was funded in October 2019. Game development took place in 2020. Patient recruitment and a clinical trial are planned for 2021. CONCLUSIONS Research on this topic is likely to significantly expand the understanding of kinesiotherapy and the impact of exergames. To the best of our knowledge, this may be one of the first studies exploring epigenetic outcomes of exergaming interventions. CLINICALTRIAL Brazilian Clinical Trials Registry/Registro Brasileiro de Ensaios Clínicos (ReBEC) RBR-9tdrmw; https://ensaiosclinicos.gov.br/rg/RBR-9tdrmw. INTERNATIONAL REGISTERED REPORT DERR1-10.2196/32729

Parkinson's disease (PD) is a neurodegenerative disorder with significant motor disabilities and cognitive decline. Importantly, the imbalance of oxidative stress is related to PD physiopathology and progression. This study aimed to evaluate the impact of grape juice consumption associated with an aquatic exercise protocol on oxidative stress parameters and cognitive function in individuals with PD. The participants were randomized into two groups: grape juice group (GJG) and control group (CG) and were submitted to 4 weeks of an aquatic intervention (twice a week, approximately 60 minutes/session). The GJG also consumed 400 ml of grape juice per day (integral and conventional) during this period. Cognitive function was assessed by the Montreal Cognitive Assessment (MoCa) questionnaire. For the analysis of oxidative stress markers, specifically lipid oxidative damage (TBARS), proteins (Carbonil), acid uric and the activity of antioxidant enzymes (superoxide dismutase, glutathione peroxidase and catalase), blood collection were done before and after intervention. No changes were observed in cognitive function after intervention in both groups. Regarding biomarkers, a reduction of antioxidant enzymes, thiobarbituric acid reactive substances (TBARS) and uric acid was observed in both groups. However, only the GJG showed a significant reduction on protein oxidation levels after intervention. In conclusion, the consumption of grape juice associated with an aquatic exercise protocol might be consider an effective alternative to reduce the oxidative damage in PD, reinforcing the importance of this intervention in promoting beneficial impact in this population., Grape juice; Aquatic exercise; Oxidative stress; Cognition

Depressive conditions precipitated by repeated stress are a major socio-economical burden in Western countries. Previous studies showed that ATP-P2X7 receptors (P2X7R) and adenosine A2A receptors (A2AR) antagonists attenuate behavioral modifications upon exposure to repeated stress. Since it is unknown if these two purinergic modulation systems work independently, we now investigated a putative interplay between P2X7R and A2AR. Adult rats exposed to restraint stress for 14 days displayed an anxious (thigmotaxis, elevated plus maze), depressive (anhedonia, increased immobility), and amnesic (modified Y maze, object displacement) profile, together with increased expression of Iba-1 (a marker of microglia “activation”) and interleukin-1β (IL1β) and tumor necrosis factor α (TNFα; proinflammatory cytokines) and an up-regulation of P2X7R (mRNA) and A2AR (receptor binding) in the hippocampus and prefrontal cortex. All these features were attenuated by the P2X7R-preferring antagonist brilliant blue G (BBG, 45 mg/kg, i.p.) or by caffeine (0.3 g/L, p.o.), which affords neuroprotection through A2AR blockade. Notably, BBG attenuated A2AR upregulation and caffeine attenuated P2X7R upregulation. In microglial N9 cells, the P2X7R agonist BzATP (100 μM) or the A2AR agonist CGS26180 (100 nM) increased calcium levels, which was abrogated by the P2X7R antagonist JNJ47965567 (1 μM) and by the A2AR antagonist SCH58261 (50 nM), respectively; notably JNJ47965567 prevented the effect of CGS21680 and the effect of BzATP was attenuated by SCH58261 and increased by CGS21680. These results provide the first demonstration of a functional interaction between P2X7R and A2AR controlling microglia reactivity likely involved in behavioral adaptive responses to stress and are illustrative of a cooperation between the two arms of the purinergic system in the control of brain function.

A growing body of evidence has suggested that the imbalance of epigenetic markers and oxidative stress appears to be involved in the pathophysiology and progression of stroke. Thus, strategies that modulate these biomarkers might be considered targets for neuroprotection and novel therapeutic opportunities for these patients. Physical exercise has been reported to induce changes in these epigenetic markers and improve clinical outcomes in different populations. However, little is reported on this in post-stroke patients. The purpose of this study was to investigate the effect of a single exercise session with WalkAide functional electrical stimulation (FES) on cognitive performance, clinical functional parameters, oxidative stress and epigenetic modulation in post-stroke individuals. In this crossover design study, 12 post-stroke individuals aged 54-72 years of either sexes were included and subjected to a single session of exercise (45 minutes) without WalkAide functional electrical stimulation (EXE alone group), followed by another single session of exercise (45 minutes) with WalkAide functional electrical stimulation (EXE + FES group). The clinical functional outcome measures, cognitive performance and blood collections for biomarker measurements were assessed pre- and post-intervention. After intervention, higher Berg Balance Scale scores were obtained in the EXE + FES group than in the EXE alone group. There was no significant difference in the Timed Up and Go test results post-intervention between EXE alone and EXE + FES groups. After intervention, a better cognitive performance was found in both groups compared with before the intervention. After intervention, the Timed Up and Go test scores were higher in the EXE + FES group than in the EXE alone group. In addition, the intervention induced lower levels of lipid peroxidation. After intervention, carbonyl level was lower, superoxide dismutase activity and superoxide dismutase/catalase activity ratio were higher in the EXE + FES group, compared with the EXE group alone. In each group, both histone deacetylase (HDAC2) and histone acetyltransferase activities were increased after intervention compared with before the intervention. These findings suggest that a single exercise session with WalkAide FES is more effective on balance ability and cognitive performance compared with conventional exercise alone in post-stroke patients. This is likely to be related to the regulation of oxidative stress markers. The present study was approved by the Research Ethics Committee of the Methodist University Center-IPA (approval No. 2.423.376) on December 7, 2017 and registered in the Brazilian Registry of Clinical Trials-ReBEC (RBR-9phj2q) on February 11, 2019.

Our aim was to evaluate the impact of a single bout of exercise, consisting of a gait training session with body weight support (BWS), on histone acetylation status (global histone H4 and H3 acetylation levels), brain-derived neurotrophic factor (BDNF) levels, and oxidative stress markers in peripheral blood of individuals with chronic spinal cord injury (SCI). We also set out to compare these responses with those recorded after gait training performed using a walker and with no BWS. The subjects (nearly all with an incomplete spinal cord lesion) were each submitted to two 60-minute experimental sessions on separate days with a 1- week wash-out period between the interventions. The order of the sessions was randomized. Blood samples were collected before and after each experimental trial for measurement of biomarkers. The histone acetylation status and BDNF levels remained unchanged after both interventions. After the treadmill training, the participants showed a strong increase in levels of oxidative stress markers [plasma advanced oxidation protein products (AOPPs), nitrite and thiobarbituric acid-reactive substances] without changes in antioxidant mediators. Instead, elevations in AOPP and nitrite concentrations, in addition to increased levels of glutathione and catalase activity, were found after the walker training. A single bout of gait training, be it conducted on a treadmill with BWS or using a walker without BWS, is not able to alter BDNF levels and histone acetylation status in SCI patients. However, these trials can modulate oxidative stress parameters, seemingly in a protocol-dependent manner.

Parkinson's disease is a neurodegenerative disease. Oxidative stress, i.e., the imbalance between the generation of reactive oxygen species and the antioxidant defense capacity of the body, plays an important role in the pathogenesis of this disease. Physical exercise can regulate oxidative stress. The purpose of this study was to analyze the short- and long-term effects of an aquatic exercise program on oxidative stress levels in patients with Parkinson's disease. The aquatic exercise program was carried out during 1 month with two sessions per week (1 hour/session). Blood samples were collected at four different time points: pre-intervention, immediately, 48 hours, and 30 days after the first session of aquatic exercise program. Our results revealed that water-based programs modulated antioxidant enzyme activity, increased superoxide dismutase activity, reduced catalase activity, and increased the ratio of superoxide dismutase activity to catalase activity in patients with Parkinson's disease. Compared with pre-intervention and 48 hours after the first session of aquatic exercise program, superoxide dismutase activity was higher and catalase activity was lower immediately and 30 days after the first session. Our results demonstrated that aquatic exercise program could modulate oxidative stress, mainly by the effect of antioxidant enzyme activity. These results could better help understand the target of oxidative stress in Parkinson's disease. This study was approved by the Ethics Committee of Centro Universitario Metodista IPA (approval No. 1.373.911) on August 9, 2019 and registered with REBEC (registration number: RBR-6NJ4MK).

Introduction Some foods are also demonstrated benefits, such as anti-inflammatory, antioxidant, and ergogenic activity, similar to that of sports supplements. Grape juice has been considered an important source of polyphenols and these compounds could promote positive effects to the sports players. In this sense, the objective was to evaluate the effects of purple grape juice consumption on indicators of oxidative stress, inflammation, muscle damage, global histone H4 acetylation levels, and muscle strength and muscle power in volleyball athletes. Methods This is a randomized double-blind clinical trial in which 12 male volleyball players (16 ± 0.6 years old) participated in three different moments with match simulation: control (without beverage) (WB), grape juice (GJ) and placebo (PLA) (400 mL/day of grape juice or placebo (maltodextrin) for 14 days in a cross-over model). Before and immediately after each match, blood collection for analysis of indicators of systemic redox status, systemic concentrations of Interferon-γ (IFN- γ) and Interleukin-4 (IL-4), muscle damage, by Creatine Kinase (CK-NAC) and levels of global histone H4 acetylation were performed, as well as handgrip strength (HG) and lower limb power tests. Results Consumption of grape juice significantly reduced lipid peroxidation (p = 0.04) and Deoxyribonucleic Acid (DNA) damage (p = 0.01) after the match. IFN-γ levels, IL-4, CK-NAC, and histone H4 acetylation post-match did not alter with the grape juice consumption. Lower limb power improved after acute exercise in WB and GJ conditions (p Conclusion In this pilot trial, the intake of grape juice for two weeks seems to reduce the protein oxidation and DNA damage by intermittent physical exercise, without epigenetics influence.

Background Kinesiotherapy is an option to mitigate worsening neuropsychomotor function due to human aging. Moreover, exergames are beneficial for the practice of physical therapy by older patients. Physical exercise interventions are known to alter the epigenome, but little is known about their association with exergames. Objective We aim to evaluate the effects of kinesiotherapy with exergaming on older women’s epigenetic marks and cognitive ability, as well as on their clinical functional variables. Our hypothesis states that this kind of therapy can elicit equal or even better outcomes than conventional therapy. Methods We will develop a virtual clinic exergame with 8 types of kinesiotherapy exercises. Afterward, we will conduct a 1:1 randomized clinical trial to compare the practice of kinesiotherapy with exergames (intervention group) against conventional kinesiotherapy (control group). A total of 24 older women will be enrolled for 1-hour sessions performed twice a week, for 6 weeks, totaling 12 sessions. We will assess outcomes using epigenetic blood tests, the Montreal Cognitive Assessment test, the Timed Up and Go test, muscle strength grading in a hydraulic dynamometer, and the Game Experience Questionnaire at various stages. Results The project was funded in October 2019. Game development took place in 2020. Patient recruitment and a clinical trial are planned for 2021. Conclusions Research on this topic is likely to significantly expand the understanding of kinesiotherapy and the impact of exergames. To the best of our knowledge, this may be one of the first studies exploring epigenetic outcomes of exergaming interventions. Trial Registration Brazilian Clinical Trials Registry/Registro Brasileiro de Ensaios Clínicos (ReBEC) RBR-9tdrmw; https://ensaiosclinicos.gov.br/rg/RBR-9tdrmw. International Registered Report Identifier (IRRID) DERR1-10.2196/32729

Extracellular ATP is a danger signal to the brain and contributes to neurodegeneration in animal models of Alzheimer's disease through its extracellular catabolism by CD73 to generate adenosine, bolstering the activation of adenosine A2A receptors (A2AR). Convulsive activity leads to increased ATP release, with the resulting morphological alterations being eliminated by A2AR blockade. However, it is not known if upon convulsions there is a CD73-mediated coupling between ATP release and A2AR overactivation, causing neurodegeneration. We now show that kainate-induced convulsions trigger a parallel increase of ATP release and of CD73 and A2AR densities in synapses and astrocytes of the mouse hippocampus. Notably, the genetic deletion of CD73 attenuates neuronal degeneration but has no impact on astrocytic modifications in the hippocampus upon kainate-induced convulsions. Furthermore, kainate-induced convulsions cause a parallel deterioration of hippocampal long-term potentiation (LTP) and hippocampal-dependent memory performance, which is eliminated by knocking out CD73. This demonstrates the key role of the ATP release/CD73/A2AR pathway to selectively control synaptic dysfunction and neurodegeneration following an acute brain insult, paving the way to consider CD73 as a new therapeutic target to prevent neuronal damage upon acute brain damage. Supported by La Caixa Foundation (LCF/PR/HP17/52190001).

The present study aimed to analyze the short-and long-term effects of an aquatic exercise program on plasma brain-derived neurotrophic factor (BDNF) levels in individuals with Parkinson's disease (PD). The aquatic exercise program lasted one month, and consisted of two sessions per week (1 hour per session). Blood samples were collected at four different timepoints: pre-intervention (T0), immediately after the first session (T1), 48 hours after the first session (T2), and 1 month after the intervention (T3). We found a significant decrease in BDNF levels at T2 vs T1 (p0.05). However, no changes were observed at the other time-points. Our results demonstrated that the intervention reduced plasma BDNF levels in PD individuals in a time-dependent manner: specifically, we observed acute effects, but no delayed effects.

Epigenetic changes have been shown to be associated with both aging process and aging-related diseases. There is evidence regarding the benefits of physical activity on the functionality, cognition, and quality of life of institutionalized older adults, however, the molecular mechanisms involved are not elucidated. The purpose of this pilot study was to investigate the effects of a multimodal exercise intervention on functional outcomes, cognitive performance, quality of life (QOL), epigenetic markers and brain-derived neurotrophic factor (BDNF) levels among institutionalized older adult individuals. Participants (n = 8) without dementia who were aged 73.38 ± 11.28 years and predominantly female (87.5%) were included in this quasi-experimental pilot study. A multimodal exercise protocol (cardiovascular capacity, strength, balance/agility and flexibility, perception and cognition) consisted of twice weekly sessions (60 minutes each) over 8 weeks. Balance (Berg Scale), mobility (Timed Up and Go test), functional capacity (Six-Minute Walk test), cognitive function (Mini-Mental State Examination) and QOL (the World Health Organization Quality of Life-BREF Scale questionnaire) were evaluated before and after the intervention. Blood sample (15 mL) was also collected before and after intervention for analysis of biomarkers global histone H3 acetylation and brain-derived neurotrophic factor levels. Significant improvements were observed in cognitive function, balance, mobility, functional capacity and QOL after the intervention. In addition, a tendency toward an increase in global histone H3 acetylation levels was observed, while brain-derived neurotrophic factor level remained unchanged. This study provided evidence that an 8-week multimodal exercise protocol has a significant effect on ameliorating functional outcomes and QOL in institutionalized older adult individuals. In addition, it was also able to promote cognitive improvement, which seems to be partially related to histone hyperacetylation status. The Ethics Research Committee of Centro Universitário Metodista-IPA, Brazil approved the current study on June 6, 2019 (approval No. 3.376.078).

Caffeine prophylactically prevents mood and memory impairments through adenosine A(2A) receptor (A(2A)R) antagonism. A(2A)R antagonists also therapeutically revert mood and memory impairments, but it is not known if caffeine is also therapeutically or only prophylactically effective. Since depression is accompanied by mood and memory alterations, we now explored if chronic (4 weeks) caffeine consumption (0.3 g/L) reverts mood and memory impairment in helpless mice (HM, 12 weeks old), a bred-based model of depression. HM displayed higher immobility in the tail suspension and forced swimming tests, greater anxiety in the elevated plus maze, and poorer memory performance (modified Y-maze and object recognition). HM also had reduced density of synaptic (synaptophysin, SNAP-25), namely, glutamatergic (vGluT1; -22 +/- 7 %) and GABAergic (vGAT; -23 +/- 8 %) markers in the hippocampus. HM displayed higher A(2A)R density (72 +/- 6 %) in hippocampal synapses, an enhanced facilitation of hippocampal glutamate release by the A(2A)R agonist, CGS21680 (30 nM), and a larger LTP amplitude (54 +/- 8 % vs. 21 +/- 5 % in controls) that was restored to control levels (30 +/- 10 %) by the A(2A)R antagonist, SCH58261 (50 nM). Notably, caffeine intake reverted memory deficits and reverted the loss of hippocampal synaptic markers but did not affect helpless or anxiety behavior. These results reinforce the validity of HM as an animal model of depression by showing that they also display reference memory deficits. Furthermore, caffeine intake selectively reverted memory but not mood deficits displayed by HM, which are associated with an increased density and functional impact of hippocampal A(2A)R controlling synaptic glutamatergic function. NARSAD DARPA [09-68-ESR-FP-010] Fundacao para a Ciencia e para a Tecnologia [PTDC/SAU-NEU/122254/2010, PEst-C/SAU/LA0001/2013-2014] QREN [CENTRO-07-ST24-FEDER-002006] program Egide-Pessoa CAPES FCT (Ciencia sem Fronteiras)

The study aimed to compare the basal plasma levels of inflammatory markers (MCP-1, IL-1ra and IL-1β) in Parkinson Disease group (PDG) with control healthy subjects (control group, CG), as well to investigate the acute and chronic effects of an aquatic physiotherapy program on these biomarkers in PDG. Firstly, a rest blood sampling was taken from antecubital vein of the PD and CG. After, the PD individuals were submitted to a supervisioned aquatic physiotherapy program during 1 month, twice a week (60 min/session). In order to evaluate the acute and chronic effects of the intervention on the biomarkers, blood samples were in 4 times: before the exercise program (pre), immediately after the first session, 48 h after the exercise session and 1 month after the intervention. It was observed higher levels of the pro-inflammatory cytokines IL-1β and MCP-1 and reduced levels IL-1ra in PDG compared to the CG. Regarding the intervention effects in PDG, a remarkable reduction on IL-1β and MCP-1 levels at 48 h when compared to the basal were found. Furthermore, after 1 month, it was observed diminished levels of MCP-1 in combination to an increase on IL-1ra. Our data support the idea that an inflammatory status is linked to PD and that MCP-1 and IL-1ra could be taken as promising biomarkers in this condition. We also demonstrated that an aquatic physiotherapy program may offer a potential intervention able to attenuate immune responses in PD individuals in a short and long-term perspective.

Despite the characteristic etiologies and phenotypes, different brain disorders rely on common pathogenic events. Glutamate-induced neurotoxicity is a pathogenic event shared by different brain disorders. Another event occurring in different brain pathological conditions is the increase of the extracellular ATP levels, which is now recognized as a danger and harmful signal in the brain, as heralded by the ability of P2 receptors (P2Rs) to affect a wide range of brain disorders. Yet, how ATP and P2R contribute to neurodegeneration remains poorly defined. For that purpose, we now examined the contribution of extracellular ATP and P2Rs to glutamate-induced neurodegeneration. We found both in vitro and in vivo that ATP/ADP through the activation of P2Y1R contributes to glutamate-induced neuronal death in the rat hippocampus. We found in cultured rat hippocampal neurons that the exposure to glutamate (100 µM) for 30 min triggers a sustained increase of extracellular ATP levels, which contributes to NMDA receptor (NMDAR)-mediated hippocampal neuronal death through the activation of P2Y1R. We also determined that P2Y1R is involved in excitotoxicity in vivo as the blockade of P2Y1R significantly attenuated rat hippocampal neuronal death upon the systemic administration of kainic acid or upon the intrahippocampal injection of quinolinic acid. This contribution of P2Y1R fades with increasing intensity of excitotoxic conditions, which indicates that P2Y1R is not contributing directly to neurodegeneration, rather behaving as a catalyst decreasing the threshold from which glutamate becomes neurotoxic. Moreover, we unraveled that such excitotoxicity process began with an early synaptotoxicity that was also prevented/attenuated by the antagonism of P2Y1R, both in vitro and in vivo. This should rely on the observed glutamate-induced calpain-mediated axonal cytoskeleton damage, most likely favored by a P2Y1R-driven increase of NMDAR-mediated Ca2+ entry selectively in axons. This may constitute a degenerative mechanism shared by different brain diseases, particularly relevant at initial pathogenic stages., The present work was financed by Portuguese national funds via Fundação para a Ciência e a Tecnologia (FCT), under the projects EXPL/NEU-NMC/0671/2012 and PTDC/NEU-NMC/3567/2014 granted to R.J.R.; by Alzheimer Association under the project NIRG-15-361884 granted to R.J.R.; and by Santa Casa da Misericórdia and Prémio Maratona da Saúde granted to R.A.C. This work was also financed by the European Regional Development Fund (ERDF), through the Centro 2020 Regional Operational Programme under project CENTRO-01-0145-FEDER-000008:BrainHealth2020, and through the COMPETE 2020—Operational Programme for Competitiveness and Internationalization and Portuguese national funds via FCT, under the project POCI-01-0145-FEDER-007440. A.P.S. was recipient of a postdoctoral fellowship (SFRH/BPD/91683/2012); J.M.M. was supported by a postdoctoral fellowship (SFRH/BPD/107903/2015). J.L. acknowledges financial support from the Spanish Ministry of Economy and Competitiveness, through the “Severo Ochoa” Programme for Centres of Excellence in R&D (SEV—2013-0317).

Parkinson's disease (PD) is characterized by a progressive neurodegeneration in the substantia nigra and a striatal dopamine decrease. Striatal extracellular adenosine and ATP modulate the dopaminergic neurotransmission whereas guanosine has a protective role in the brain. Therefore, the regulation of their levels by enzymatic activity may be relevant to the clinical feature of PD. Here it was evaluated the extracellular nucleotide hydrolysis from striatal slices 4 weeks after a unilateral infusion with 6-OHDA into the medial forebrain bundle. This infusion increased ADP, AMP, and GTP hydrolysis by 15, 25, and 41%, respectively, and decreased GDP hydrolysis by 60%. There was no change in NTPDases1, 2, 3, 5, 6, and 5'-nucleotidase transcription. Dopamine depletion changes nucleotide hydrolysis and, therefore, alters the regulation of striatal nucleotide levels. These changes observed in 6-OHDA-lesioned animals may contribute to the symptoms observed in the model and provide evidence to indicate that extracellular purine hydrolysis is a key factor in understanding PD, giving hints for new therapies.

During the past few years, elevated blood levels of homocysteine (Hcy) have been linked to increased risk of premature coronary artery disease, stroke and thromboembolism. These processes can be also related to the ratio adenine nucleotide/adenosine, since extracellularly these nucleotides are associated with modulation of processes such as platelet aggregation, vasodilatation and coronary flow. Furthermore, there are some studies that suggest a relationship between Hcy and plasma adenosine concentrations. The sequential hydrolysis of ATP to adenosine by soluble nucleotidases constitutes one of the systems for rapid inactivation of circulating adenine nucleotides. Thus, the main objective of this study was to evaluate if Hcy can participate in the modulation of the extracellular adenine nucleotide hydrolysis by rat blood serum. Our results showed that Hcy, at final concentrations of 5.0 mM, inhibits in vitro ATP, ADP and AMP hydrolysis by 26, 21 and 16%, respectively. Also Hcy, at final concentrations of 8.0mM, inhibited the in vitro hydrolysis of ATP, ADP and AMP by 46, 44 and 44%, respectively. Kinetic analysis showed that the inhibitions of the three adenine nucleotide hydrolyses in the presence of Hcy, by serum of adult rats, is of the uncompetitive type. The IC50 calculated from the results obtained were 6.52+/-1.75 mM (n = 4), 5.18 +/- 0.64 mM (n = 3) and 5.16 +/- 1.22 mM (n = 3) for ATP, ADP and AMP hydrolysis, respectively.

The presence of severe neurological symptoms in thyroid diseases has highlighted the importance of thyroid hormones in the normal functioning of the mature brain. Since, ATP is an important excitatory neurotransmitter and adenosine acts as a neuromodulatory structure inhibiting neurotransmitters release in the central nervous system (CNS), the ectonucleotidase cascade that hydrolyzes ATP to adenosine, is also involved in the control of brain functions. Thus, we investigated the influence of hyper-and hypothyroidism on the ATP, ADP and AMP hydrolysis in hippocampal and cortical slices from adult rats. Hyperthyroidism was induced by daily injections of l -thyroxine (T4) 25 μg/100 g body weight, for 14 days. Hypothyroidism was induced by thyroidectomy and methimazole (0.05%) added to their drinking water for 14 days. Hypothyroid rats were hormonally replaced by daily injections of T4 (5 μg/100 g body weight, i.p.) for 5 days. Hyperthyroidism significantly inhibited the ATP, ADP and AMP hydrolysis in hippocampal slices. In brain cortical slices, hyperthyroidism inhibited the AMP hydrolysis. In contrast, hypothyroidism increased the ATP, ADP and AMP hydrolysis in both hippocampal and cortical slices and these effects were reverted by T4 replacement. Furthermore, hypothyroidism increased the expression of NTPDase1 and 5′-nucleotidase, whereas hyperthyroidism decreased the expression of 5′-nucleotidase in hippocampus of adult rats. These findings demonstrate that thyroid disorders may influence the enzymes involved in the complete degradation of ATP to adenosine and possibly affects the responses mediated by adenine nucleotides in the CNS of adult rats.

In this study, we have reported the kinetic and biochemical characterization of ectonucleotide pyrophosphatase/phosphodiesterase (E-NPP) activity in rat cardiac fractions, one soluble and the other enriched in vesicles derived from sarcoplasmic reticulum. Both fractions demonstrated E-NPP activities, which could be observed by extracellular hydrolysis of p-nitrophenyl-5'-thymidine monophosphate (p-Nph-5'-TMP) and other biochemical characteristics. The K(M) values for the hydrolysis of p-Nph-5'-TMP in soluble and microsomal fractions were 118.53 ± 27.28 and 91.92 ± 12.49 µM, respectively. The V(max) values calculated were 2.56 ± 0.15 and 113.87 ± 21.09 nmol p-nitrophenol/min/mg of protein in soluble and microsomal fractions, respectively. Among the compounds tested to evaluate the possible activity of other enzymes on p-Nph-5'-TMP hydrolysis, only suramin (0.25 mM) produced a significant inhibition of substrate hydrolysis. Thus, our results strongly suggest the presence of E-NPP enzymes in subcellular fractions of rat heart, which could be involved in nucleotide signalling in the cardiac tissue.

The goal of acetylcholinesterase inhibitors (AChEIs) used to treat Alzheimer's patients is an improvement in cholinergic transmission. While currently available AChEIs have limited success, a huge impediment to the development of newer ones is access to the relevant brain areas. Promnesic, anti-amnesic and AChEI properties were identified in a standardized ethanol extract from Ptychopetalum olacoides (POEE), a medicinal plant favored by the elderly in Amazon communities. The purpose of this study was to provide conclusive evidence that orally given POEE induces AChE inhibition in brain areas relevant to cognition. Histochemistry experiments confirmed that the anticholinesterase compound(s) present in POEE are orally bioavailable, inducing meaningful AChE inhibition in the hippocampus CA1 (∼33%) and CA3 (∼20%), and striatum (∼17%). Ellman's colorimetric analysis revealed that G1 and G4 AChE isoforms activities were markedly inhibited (66 and 72%, respectively) in hippocampus and frontal cortex (50 and 63%, respectively), while G4 appeared to be selectively inhibited (72%) in the striatum. Western blotting showed that POEE did not induce significant changes in the AChE immunocontent suggesting that its synthesis is not extensively modified. This study provides definitive proof of meaningful anticholinesterase activity compatible with the observed promnesic and anti-amnesic effects of POEE in mice, reaffirming the potential of this extract for treating neurodegenerative conditions where a hypofunctioning cholinergic neurotransmission is prominent. Adequate assessment of the safety and efficacy of this extract and/or its isolated active compound(s) are warranted.

The present study describes the enzymatic properties and molecular identification of 5'-nucleotidase in soluble and microsomal fractions from rat cardiac ventricles. Using AMP as a substrate, the results showed that the cation and the concentration required for maximal activity in the two fractions was magnesium at a final concentration of 1 mM. The pH optimum for both fractions was 9.5. The apparent K(m) (Michaelis constant) values calculated from the Eadie-Hofstee plot were 59.7+/-10.4 microM and 134.8+/-32.1 microM, with V(max) values of 6.7+/-0.4 and 143.8+/-23.8 nmol P(i)/min/mg of protein (means+/-S.D., n=4) from soluble and microsomal fractions respectively. Western blotting analysis of ecto-5'-nucleotidase revealed a 70 kDa protein in both fractions, with the major proportion present in the microsomal fraction. The presence of these enzymes in the heart probably has a physiological function in adenosine signalling. Furthermore, the presence of ecto-5'-nucleotidase in the microsomal fraction could have a role in the modulation of the excitation-contraction-coupling process through involvement of the Ca(2+) influx into the sarcoplasmic reticulum. The measurement of maximal enzyme activities in the two fractions highlights the potential capacity of the different pathways of purine metabolism in the heart.

Purinergic system exerts a significant influence on the modulation of pain pathways at the spinal site. Adenosine has antinociceptive properties in experimental and clinical situations, while ATP exerts pronociceptive actions in different pain models. In this study we investigated the hydrolysis of ATP to adenosine in synaptosomes from spinal cord in parallel with the nociceptive response of rats at different ages after hypothyroidism induction. Hypothyroidism elicited a significant increase in AMP hydrolysis to adenosine in synaptosomes from spinal cord of rats subjected to neonatal hypothyroidism and in 420-day-old rats submitted to thyroidectomy. Accordingly, these rats presented an analgesic response as a consequence of hypothyroidism. In contrast, the ATP hydrolysis was decreased in the spinal cord of 60-day-old hypothyroid rats in parallel with a significant increase in nociceptive response. These results indicate the involvement of adenine nucleotides in the control of the hypothyroidism-induced nociceptive response during development.

The influence of the thyroid hormones on the normal function of the mammalian central nervous system depends on the brain region and on the developmental stage. Adenine nucleotides and their products also affect the brain function; ATP is an excitatory neurotransmitter, and adenosine has inhibitory effects on neurotransmission. Thus, this study aimed to evaluate the effects of hypothyroidism on the hydrolysis of ATP to adenosine in hippocampal and cortical synaptosomes and blood serum of rats during different phases of development. Rats aged 60 and 420 days old were divided into three groups: control, sham-operated and hypothyroid. Hypothyroidism was induced in these rats by thyroidectomy and methimazole (0.05%) added to their drinking water for 14 days. Neonatal hypothyroidism was induced by adding 0.02% methimazole in the drinking water from day 9 of gestation, and continually until 14 days old. Hypothyroidism increased the AMP hydrolysis in both hippocampus and cerebral cortex synaptosomes of rats in all aged tested. In blood serum, thyroid hormones deficiency increased the AMP hydrolysis in 14-day-old rats and the hydrolysis of ATP, ADP and AMP in 60-day-old rats; however, no alteration was observed in 420-day-old rats. Thus, our results suggest the involvement of the 5′-nucleotidase in synaptic function control in hypothyroidism throughout brain development.