Effect of Exercise on Oxidant and Antioxidant Systems in Rat Kidney Tissue with Hyperthyroidism

Abstract

Oxidative stress is involved in the pathogenesis of many diseases. Hyperthyroidism is associated with increased oxidative tissue damage. The aim of this study is to investigate whether if there is any protective effect of a regular endurance exercise on oxidative stress in kidney tissues of rats with experimental hyperthyroidism. Twenty-three male Spraque Dawley rats were divided into four groups: Control, hyperthyroid, exercise and, hyperthyroid with exercise. Hyperthyroid was induced in rats by subcutaneous injections at a dosage of 250 μg L-thyroxine per kg body weight and hyperthyroidism was confirmed by the measurements of TSH, FT3 and FT4 in serum. Endurance training lasted 8 weeks and consisted of 45 minutes daily treadmill running at a speed of 23 m/minute for 5 days a week. The levels of MDA, GSH and, GSH-Px activity were measured in kidney homogenates. MDA level of the hyperthyroid group was significantly higher than those of the control group(p=0.022). On the other hand, the MDA level of the exercise group was significantly lower than the MDA level of the hyperthyroid group (p=0,001). GSH level and GSH-Px activities were lower in the hyperthyroid group comparing the control group (p<0.05). GSH level and GSH-Px activity in the exercise group were higher than compared with the hyperthyroid group (p<0.05). The results of our study show that L-thyroxine injection may increase oxidative stress by causing lipid peroxidation at kidney tissues and endurance training may decrease oxidative stress.