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Porto Alegre, Brazil

Rodrigues A.D.,University of Caxias do Sul | Scheffel T.B.,University of Caxias do Sul | Scola G.,University of Caxias do Sul | dos Santos M.T.,Centro Universitario Metodista do | And 6 more authors.
Nutrition Research

Oxidative damages in hepatocytes may be caused by epilepsy and/or anticonvulsant drugs. Epilepsy is one of the most common neurological disorders, characterized by recurrent seizures, which may increase the content of reactive oxygen species. Organic and conventional grape juices are rich in polyphenols, compounds with important antioxidant activity. It is hypothesized that organic and conventional purple grape juices may have protective effect against oxidative damage induced by pentylenetetrazole (PTZ) (a standard convulsant drug) in the liver and serum of Wistar rats. Animals (n = 16 in each group) received, by gavage, saline, organic grape juice or conventional grape juice (10 μL/g of body weight) for 17 days. Subsequently, half of the rats in each group received PTZ (60 mg/kg). After 30 minutes, the animals were euthanized by decapitation. Liver and blood samples were isolated to evaluate oxidative parameters (lipid and protein oxidation, nitric oxide metabolite content, antioxidant defenses, and protein sulfhydryl content). The results of this study showed that although organic juice contains higher polyphenol content than conventional juice, both juices conferred protection against lipid and protein oxidative damage and limited the increase in PTZ-induced nitric oxide metabolite content in the liver and serum. In addition, both juices inhibited the PTZ-induced reduction in enzymatic antioxidant defenses (superoxide dismutase and catalase activities) and sulfhydryl protein content in the liver and serum. In summary, both organic and conventional grape juices were able to reduce oxidative damage induced by PTZ in the liver and serum of Wistar rats. © 2013 Elsevier Inc. Source

Caletti G.,Federal University of Health Sciences, Porto Alegre | Almeida F.B.,Federal University of Health Sciences, Porto Alegre | Agnes G.,Federal University of Health Sciences, Porto Alegre | Nin M.S.,Federal University of Health Sciences, Porto Alegre | And 4 more authors.
Behavioural Brain Research

Diabetes mellitus is a metabolic disorder associated with higher risk for depression. Diabetic rats present depressive-like behaviors and taurine, one of the most abundant free amino acids in the brain, reverses this depressive behaviors. Because taurine is a GABAA agonist modulator, we hypothesize that its antidepressant effect results from the interaction on this system by changing α2 GABAA receptor subunit expression, beside changes on BDNF mRNA, and memory in diabetic rats. Streptozotocin-diabetic and non-diabetic Wistar rats were daily injected with 100mg/kg of taurine or saline, intraperitoneally, for 30 days. At the end of the experiment, rats were exposed to the novel object recognition memory. Later they were euthanized, the brains were weighed, and the hippocampus was dissected for α2 GABAA subunit and BDNF mRNA expression. Real-time quantitative PCR (qPCR) showed that diabetic rats presented lower α2 GABAA subunit and BDNF mRNA expression than non-diabetic rats and taurine increased both parameters in these sick rats. Taurine also reversed the lower brain weight and improved the short-term memory in diabetic rats. Thus, the taurine antidepressant effect may be explained by interference with the GABA system, in line to its neuroprotective effect showed here by preventing brain weight loss and improving memory in diabetic rats. © 2015 Elsevier B.V. Source

Souza R.L.,Centro Universitario Metodista do | Cardoso M.C.A.F.,Federal University of Health Sciences, Porto Alegre
Revista Neurociencias

Objective. To establish the difference between the disorders of fluency and prosody. Method. It is a review of literature on the fluency and Prosody front to their disorders. Results. Fluency is characterized by the ability to produce a spontaneous fluid speech and its disorders are termed as fluency disorders, in which occur disturbances in rhythm, intonation and speed, when there is stress to speak. These disorders can be classified as normal, abnormal or ambiguous. The Prosody is defined as the element that verbal oral production structure is capable of segmenting speech sounds that when formulating the syllables, raises a rhythmic structure. Their disorders are classified into aprosodia and hiperprosodia. Conclusion. The characterization of prosody and of fluency mixes in many papers. Although different the fluency disorders and disturbances of prosody carry differences as to its interpretation in the light of the theoretical bases that mark their concepts. Source

Loss E.S.,Federal University of Rio Grande do Sul | Jacobus A.P.,Federal University of Rio Grande do Sul | Jacobus A.P.,Centro Universitario Metodista do | Wassermann G.F.,Federal University of Rio Grande do Sul
Life Sciences

This minireview describes the rapid signaling actions of follicle stimulating hormone (FSH) and testosterone in immature Sertoli cells mainly related to Ca 2+ inflow and the electrophysiological changes produced by hormones. The rapid membrane actions of FSH occur in a time frame of seconds to minutes, which include membrane depolarization and the stimulation of 45Ca 2+ uptake. These effects can be prevented by pertussis toxin (PTX), suggesting that they are likely mediated by Gi-protein coupled receptor activation. Furthermore, these effects were inhibited by verapamil, a blocker of the L-type voltage-dependent Ca 2+ channel (VDCC). Finally, FSH stimulation of 45Ca 2+ uptake was inhibited by the (phosphoinositide 3-kinase) PI3K inhibitor wortmannin. These results suggest that the rapid action of FSH on L-type Ca 2+ channel activity in Sertoli cells from pre-pubertal rats is mediated by the Gi/Gβγ/ PI3Kγ pathway, independent of its effects on insulin-like growth factor type I (IGF-I). Testosterone depolarizes the membrane potential and increases the resistance and the 45Ca 2+ uptake in Sertoli cells of the seminiferous tubules of immature rats. These actions were nullified by diazoxide (K + ATP channel opener). Testosterone actions were blocked by both PTX and the phospholipase C (PLC) inhibitor U73122, suggesting the involvement of PLC - phosphatidylinositol 4-5 bisphosphate (PIP2) hydrolysis via the Gq protein in the testosterone-mediated pathway. These results indicate that testosterone acts on the Sertoli cell membrane through the K + ATP channels and PLC-PIP2 hydrolysis, which closes the channel, depolarizes the membrane and stimulates 45Ca 2+ uptake. These results demonstrate the existence of rapid non-classical pathways in immature Sertoli cells regulated by FSH and testosterone. © 2011 Elsevier Inc. Source

Escott G.M.,Federal University of Rio Grande do Sul | De Castro A.L.,Federal University of Rio Grande do Sul | Jacobus A.P.,Centro Universitario Metodista do | Loss E.S.,Federal University of Rio Grande do Sul
Biochimica et Biophysica Acta - Biomembranes

Insulin and insulin-like growth factor 1 (IGF-I) are capable of activating similar intracellular pathways. Insulin acts mainly through its own receptor, but can also activate the IGF-I receptor (IGF-IR). The aim of this study was to investigate the involvement of the IGF-IR in the effects of insulin and IGF-I on the membrane potential of immature Sertoli cells in whole seminiferous tubules, as well as on calcium, amino acid, and glucose uptake in testicular tissue of immature rats. The membrane potential of the Sertoli cells was recorded using a standard single microelectrode technique. In calcium uptake experiments, the testes were pre-incubated with 45Ca2 +, with or without JB1 (1 μg/mL), and then incubated with insulin (100 nM) or IGF-I (15 nM). In amino acid and glucose uptake experiments, the gonads were pre-incubated with or without JB1 (1 μg/mL) and then incubated with radiolabeled amino acid or glucose analogues in the presence of insulin (100 nM) or IGF-I (15 nM). The blockade of IGF-IR with JB1 prevented the depolarising effects of both insulin and IGF-I on membrane potential, as well as the effect of insulin on calcium uptake. JB1 also inhibited the effects of insulin and IGF-I on glucose uptake. The effect of IGF-I on amino acid transport was inhibited in the presence of JB1, whereas the effect of insulin was not. We concluded that while IGF-I seems to act mainly through its cognate receptor to induce membrane depolarisation and calcium, amino acid and glucose uptake, insulin appears to be able to elicit its effects through IGF-IR, in seminiferous tubules from immature rats. © 2014 Elsevier B.V. Source

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