Free radical changes in rat muscle tissue after exercise

Intense exercise accompanied by a manifold increase in oxygen utilization o ver resting conditions has been shown to elevate the probability of the app earance of free radicals. One of the effects of free radicals appears to be the peroxidation of cell membrane lipids resulting in malondialdehyde form ation, which is detrimental to cell function. A common method for the measu rement of malondialdehyde involves a reaction with thiobarbituric acid. The aim of this study was to evaluate the influence of exercise on concentrati ons of thiobarbituric acid-reactive substances (TBARS) in the gastrocnemius and soleus muscles of rats. Thirty male rats were used in this study. Sole us and gastrocnemius muscle biopsies were performed and TEARS levels were s tudied in these two muscles. The rats were randomly assigned to three group s of ten each. Group A was the control group and did not perform exercise. In group B1 gastrocnemius and soleus muscle biopsies were performed immedia tely after exercise, and in group C muscle biopsies were performed on the 2 nd postexercise day. The exercise resulted in a significant increase in TEA RS in the gastrocnemius muscle. In the soleus, TEARS also increased, but th is was not statistically significant. In conclusion, exercise-induced free radical changes may depend on the muscle type studied.