Short-term exercise training improves cardiac function associated to a better antioxidant response and lower type 3 iodothyronine deiodinase activity after myocardial infarction

Aims: We assessed the effects of a short-term exercise training on cardiac function, oxidative stress markers, and type 3 iodothyronine deiodinase (D3) activity in cardiac tissue of spontaneously hypertensive rats (SHR) following experimental myocardial infarction (MI). Methods: Twenty-four SHR (aged 3 months) were allocated to 4 groups: sham+sedentary, sham+trained, MI+sedentary and MI+trained. MI was performed by permanent ligation of the coronary artery. Exercise training (treadmill) started 96 hours after MI and lasted for 4 weeks (~60% maximum effort, 4x/week and 40 min/day). Cardiac function (echocardiography), thioredoxin reductase (TRx), total carbonyl levels, among other oxidative stress markers and D3 activity were measured. A Generalized Estimating Equation was used, followed by Bonferroni’s test (p<0.05). Results: MI resulted in an increase in left ventricular mass (p = 0.002) with decreased cardiac output (~22.0%, p = 0.047) and decreased ejection fraction (~41%, p = 0.008) as well as an increase in the carbonyl levels (p = 0.001) and D3 activity (~33%, p<0.001). Exercise training resulted in a decrease in left ventricular mass, restored cardiac output (~34%, p = 0.048) and ejection fraction (~20%, p = 0.040), increased TRx (~85%, p = 0.007) and reduced carbonyl levels (p<0.001) and D3 activity (p<0.001). Conclusions: Our short-term exercise training helped reverse the effects of MI on cardiac function. These benefits seem to derive from a more efficient antioxidant response and lower D3 activity in cardiac tissue

Effect of Antioxidant Treatment on Fibrogenesis in Rats with Carbon Tetrachloride-Induced Cirrhosis

Aim. This study aimed to assess the antioxidant activity of quercetin (Q) in an experimental model of cirrhosis induced by CCl4 inhalation. Materials and Methods. We used 25 male Wistar rats (250 g) that were divided into 3 groups: control (CO), CCl4, and CCl4 + Q. The rats were subjected to CCl4 inhalation (2x/week) for 16 weeks, and they received phenobarbital in their drinking water at a dose of 0.3 g/dL as a P450 enzyme inducer. Q (50 mg/Kg) was initiated intraperitoneally at 10 weeks of inhalation and lasted until the end of the experiment. Statistical analysis was by ANOVA Student Newman-Keuls (mean ± SEM), and differences were considered statistically significant when P < 0.05. Results. After treatment with quercetin, we observed an improvement in liver complications, decreased fibrosis, as analyzed by picrosirius for the quantification of collagen, and decreased levels of matrix metalloproteinase 2 (MMP-2) compared with the CCl4 group. It also reduced oxidative stress, as confirmed by the decrease of substances reacting to thiobarbituric acid (TBARS), the increased activity of antioxidant enzymes, and the reduced glutathione ratio and glutathione disulfide (GSH/GSSG). Conclusion. We suggest that the use of quercetin might be promising as an antioxidant therapy in liver fibrosis

Efeito do treinamento físico sobre marcadores de estresse oxidativo e função endotelial em indivíduos sedentários de meia idade do sexo masculino

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Efeito do treinamento físico sobre marcadores de estresse oxidativo e função endotelial em indivíduos sedentários de meia idade do sexo masculino

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Correlação entre valores de força muscular mensurados pelos testes isocinético, isométrico e de 1RM em individuos de meia idade

The assessment of muscular strength production is very important in different subjects. However, different assessment methods can measure different phenomena. The aim of the present study was to calculate the correlations among values of one maximum repetition (1RM), isokinetic (at 60º/s) and isometric peak torque (PT) of unilateral knee extension in middle-aged men. Fourteen subjects performed the 1RM, isokinetic and isometric tests of unilateral knee extension. In order to calculate the correlations the Pearson’s correlation coefficient was used. Strong correlations were observed between the isokinetic and isometric peak torque (PT) values (r = 0.78) and between the isokinetic PT and 1RM values (r = 0.72). Between the 1RM and isometric values the relationship was moderate (r = 0.53). Several factors could be responsible to the different levels of correlation found, such as the specificity of the contraction type and the muscle activation pattern. The correlation levels found indicate that the results of these three different tests are related to each other