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Introduction: Production of free radicals and reactive oxygen species is an integral part of aerobic metabolism. Disturbance of the balance between the production of free radicals and antioxidant system against them produces oxidative stress. Paraquat toxicity is induction of oxidative stress. However, the aim of our study was to evaluate oxidative stress in blood samples of workers in a pesticide factory formulating paraquat.
Materials and Methods: In this study we measured lipid peroxidation (LPO) with thiobarbituric assay (TBARS), total antioxident power (FRAP) and SH groups between workers in pesticide factories (case group) and health subjects (control group).
Results: Oxidative stress was significantly higher (p<0.001) in LPO, significantly lower (p<0.001) in TBARS and significantly lower (p<0.001) in SH groups in the case group compared to control group
Conclusion: It is concluded that chronic exposure of workers in their workplace to paraquat producess oxidative stress that could be prevented by well known nutritional antioxidant supplements.

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Abstract Background: Oxidative stress is strongly related to diabetes and its complications. The aim of this study is to evaluate the effect of experimental diabetes on oxidative stress indexes in the heart tissue and effect of regular swimming on it. Materials and Methods: In experimental-practical study, 40 male Wister rats divided to four groups (n=10): control, control with exercise, diabetic, diabetic with exercise. Diabetes was induced by a single dose injection of Streptozotocin (50mg/Kg, i.p). Study time was 8 weeks. At the end of period, rats were anesthetized by Sodium Pentobarbital (50mg/Kg, i.p) and left ventricle dissociated and maintenance in -80 ºC. Super oxide Dismutase (SOD), Glutathione Peroxides (GPX), Glutathione Reductase (GR) and Catalase (CAT) activities as enzymatic antioxidant status and Malonyl Dealdehyde (MDA) level as index of lipid peroxidation of the tissue in superior layer of tissue homogenization were measured. Results: Diabetes induction significantly reduced CAT and GR activities in heart tissue of diabetic rats compared with control. Also MDA level increased significantly in diabetic-non exercised rats compared with control. Total Glutathione level was similar in all groups. Conclusion: Swimming by preventing in reduction of CAT and GR activities and MDA level of heart tissue has beneficial effects in prevention of cardiovascular complications caused by oxidative stress in diabetes mellitus.

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Background: Endurance training can lead to tissue damage and destruction by creating oxidative stress. But, it seems that exhaustive and endurance swimming indicated different results with each other. The purpose of this research was to compare two kinds of endurance swimming training on levels of LDH, CK and MDA in male Wistar rats.

Materials and Methods: 18 male Wistar rats with 12 weeks old, weighting 250 to 300 g, were randomly divided into three groups (6 in each): 1) endurance swimming (EN), 2) exhaustive swimming (EX) and 3) Control (C). Both groups swam for 1 h/d and 5 d/w for 10 weeks. Swimming duration in EX groups was increased progressively by fiveth weeks, by 30 min/week, reaching 3 h/d by final 3 weeks of traninig protocol. In this duration, C group didn't receive any intervention. One day after the end of training protocol, blood samples of rats were obtained on vena cava. The activity of lactate dehydrogenase (LDH) and creatine kinase (CK) was measured with DGKC method and malondialdehyde (MDA) through reaction with TBA. Results were analyzed using the one- way ANOVA followed by a Tukey test. Significant level was 0.05.

Results: EN groups significantly increased the levels of CK compared with EX and C groups (p=0.001), when indicated significantly lesser levels of MDA than C group (p=0.011). But, no significantly difference observed in the levels of LDH.

Conclusion: It seems that endurance swimming creates more muscle damage, while were generates lesser lipid peroxidation.