In conclusion, under our experimental conditions, chronic stanozolol administration induced mild cardiovascular side effects that were partly attenuated by melatonin treatment. However, these results showed that the combination of melatonin and exercise could minimize the stanozolol side effects in the cardiovascular system.

SummaryBackground: Several drugs can cause prolonged QT interval, as well as prolonged QT dispersion (QTd) in electrocardiographic (EKG) recordings. QTd may be a potentially sensitive marker of increased risk of cardiac arrhythmias and sudden cardiac death. Metformin is an effective antihyperglycemic agent used in the treatment of diabetes. However, studies have correlated dose-dependent effects of metformin on glycemia and cardiovascular risk markers.

In tumor-bearing rats, most of the serum amino acids are used for synthesis and oxidation processes by the neoplastic tissue. In the present study, the effect of Walker 256 carcinoma growth on the intestinal absorption of leucine, methionine and glucose was investigated in newly weaned and mature rats. Food intake and carcass weight were decreased in newly weaned (NT) and mature (MT) rats bearing Walker 256 tumor in comparison with control animals (NC and MC). The tumor/carcass weight ratio was higher in NT than in MT rats, whereas nitrogen balance was significantly decreased in both as compared to control animals. Glucose absorption was significantly reduced in MT rats (MT = 47.3 ± 4.9 vs MC = 99.8 ± 5.3 nmol min -1 cm -1 , Kruskal-Wallis test, P<0.05) but this fact did not hamper the evolution of cancer. There was a significant increase in methionine absorption in both groups (NT = 4.2 ± 0.3 and MT = 2.0 ± 0.1 vs NC = 3.7 ± 0.1 and MC = 1.2 ± 0.2 nmol min -1 cm -1 , Kruskal-Wallis test, P<0.05), whereas leucine absorption was increased only in young tumor-bearing rats (NT = 8.6 ± 0.2 vs NC = 7.7 ± 0.4 nmol min -1 cm -1 , Kruskal-Wallis test, P<0.05), suggesting that these metabolites are being used for synthesis and oxidation processes by the neoplastic cells, which might ensure their rapid proliferation especially in NT rats.

The parenteral or oral administration of monosodium glutamate (MSG) has been reported to have a deleterious effect on the hypothalamic arcuate nucleus, which changes appetite control. This alteration in function may lead to obesity and disorders related to metabolic syndrome, such as alterations in carbohydrate metabolism (glucose and insulin resistance), dyslipidemia and cardiovascular disease. This study evaluates the induction of metabolic alterations due to subchronic consumption of diets containing MSG at levels of 1.0%, 2.5% and 5.0%. Initially the animals (newborn male Wistar rats) consumed the diets containing MSG for a period of 70 days. At the end of this period diabetes was induced by streptozotocin (STZ) and the rats maintained on the same diets for additional 21 days. The induction of diabetes is based on the susceptibility of diabetic animals to metabolic disorders. Methods capable of evaluating the entire metabolic profile of the diabetic condition were used, including biochemical tests and tests able to detect alterations in the organs usually affected by this disease. It was concluded that the consumption of diets containing up to 5.0% MSG did not change the studied parameters for both: diabetic or non-diabetic animals. The alterations observed in the diabetic animals mainly reflected metabolic changes caused by the disease and were not related to the administration of MSG.

Background: Hypertensive condition can lead to abnormalities in heart structure and electrical activity. The electrocardiogram (ECG) is a recording of the electrical activity of the heart and widely used to diagnose and detect heart problem. Objective: We conducted a comparative ECG analysis between two hypertension models (L-NAME and SHR) and their controls (Wistar and Wistar-Kyoto) at six and 15 th week of age. Methods: Blood pressure was measured at the end of the 15 th week, and electrocardiography was performed at six and 15 weeks of age in anaesthetized rats. Data normality was confirmed by Kolmogorov-Smirnov test followed by unpaired Student's t-test and the Mann-Whitney for parametric and non-parametric data, respectively. Results are expressed as mean ± SD. The accepted level of significance was set at p < 0.05. Results: L-NAME exhibited prolongation of JT and QT intervals and SHR showed a decrease in heart rate when compared to Wistar-Kyoto and L-NAME. Wistar-Kyoto exhibited short PR interval with increased QRS complex, and only QT prolongation at 15 weeks compared to Wistar. Conclusions: All the hypertension models used in this study featured an increase in blood pressure. However, while SHR showed cardiac dysfunction, L-NAME exhibited changes in ventricular performance. These results may guide future studies on different types and models of hypertension.

These findings suggest that suramin may be a new adjunctive therapy to help improve cardiomyopathy in DMD.

Ratos Wistar machos foram expostos por via oral, durante 28 dias, a 1/10 do valor da DL50 (concentração letal) da permetrina (PMT) ou deltametrina (DMT). O objetivo deste estudo foi determinar os resíduos de PMT e DMT no fígado e coração dos ratos ao final do período de exposição e avaliar o efeito nos níveis de resíduos devido à ingestão de pectina e celulose na dieta. Os analitos foram extraídos em acetonitrila e a limpeza dos extratos foi realizada por extração em fase sólida com florisil antes da análise por GC-ECD (cromatografia gasosa com captura de elétrons). Para PMT, os limites de quantificação (LOQ) foram 1,0 e 0,2 μg g -1 e para DMT 0,9 e 0,2 μg g -1 para fígado e coração, respectivamente. Não foi verificada a presença de resíduos de PMT ou DMT acima do LOQ do método, tanto no fígado como no coração dos animais expostos.For 28 days male Wistar rats were submitted to oral exposure with 1/10 of the LD50 value of permethrin (PMT) or deltamethrin (DMT). The aim of this study was to determine the residues of PMT and DMT in the liver and heart of the rats at the end of the exposure period, as well as to evaluate the effect of ingesting pectin and cellulose via the diet. The analytes were extracted with acetonitrile and the extracts were cleaned up by solid phase extraction with florisil before GC-ECD (gas chromatography coupled with an electron-capture detector) analysis. For PMT, the limits of quantitation (LOQ) were 1.0 and 0.2 μg g -1 and for DMT 0.9 and 0.2 μg g -1 for liver and heart, respectively. No PMT or DMT residues were verified above the LOQ of the method in either the liver or heart of the exposed animals.Keywords: permethrin, deltamethrin, pyrethroids, insecticide residues, subchronic toxicity IntroductionPyrethroid pesticides are used in agriculture to control insects in vegetables, fruits and field crops, in public health to control diseases caused by vectors, and as a veterinary drug against ectoparasites. These agents do not persist in the environment and tend to exhibit slow development of insect resistance. 1 In general, pyrethroids are more effective against a wider range of insect pests and furthermore have a much lower mammal-to-insect toxicity ratio than their organochlorine, organophosphate and carbamate counterparts. 2 Nevertheless, the widespread use of these insecticides has lead to an increased exposure of workers and the ecosystem, 3 increasing the possibility of their entering the food chain via the meat or via their residues in fruits, vegetables and water. 4,5 The acute neurotoxicity of pyrethroids has been well characterized in several reviews. 1,6,7 However, although cardiovascular manifestations frequently accompany exposure to these compounds, their cardiotoxicity appears to have been little studied. 8,9 On the other hand, histological changes and alterations in the biochemical parameters were reported in rats after a single oral exposure to a-cypermethrin, 10 and residual concentrations of deltamethrin were found in several rat tissues after repeated oral exposure to th...

A síntese de hormônios tireoideanos depende fundamentalmente da captação de iodo do meio extracelular para o interior do tireócito. Esse processo é mediado por uma glicoproteína transmembrânica denominada simportador sódio/iodeto, que transporta iodeto para o interior do tireócito, juntamente com dois íons sódio em um processo de cotransporte. Esse processo é orquestrado pelo potencial eletroquímico gerado pela bomba Na+/K+ ATP´ase dependente. O simportador sódio/iodeto também está envolvido no transporte ativo de iodeto em tecidos extratireoideos, tais como glândulas salivares, mucosa gástrica e a mama em lactação. A alta capacidade de acumular iodeto pelo tireócito constitui a base do diagnóstico cintilográfico e também da terapêutica com radioiodo em situações de hiperfunção tireoidea, como, por exemplo, na doença de Graves. Algumas mutações no simportador sódio/iodeto geram prejuízo no transporte de iodeto para o tireócito, resultando em hipotireoidismo congênito; além disso, o simportador sódio/iodeto pode tornar-se alvo de imunocomplexos, como, por exemplo, nas doenças tireoideanas autoimunes. Finalmente, o estudo molecular do simportador sódio/iodeto apresenta importância em muitas áreas, que compreendem desde proteínas transportadoras até o diagnóstico e tratamento de cânceres em tecidos tireoidianos e extratireoideos. Este artigo objetivou descrever o simportador sódio/iodeto presente na glândula tireoide, destacando sua sequência de resíduos de aminoácidos, topologia e todos os demais aspectos pertinentes a sua estrutura e função. Foi desenvolvido através de revisão sistemática da literatura nacional e internacional pelo indexador Medline/PubMed, utilizando os unitermos: iodeto, tireoide, transportador, topologia, sequência de resíduos de aminoácidos e estrutura.Termos de indexação: Glândula tireoide. Iodo. Simportadores.