ANTIOXIDANT ENZYME-ACTIVITIES IN THE LYMPHOID ORGANS AND MUSCLES OF RATS FED FATTY ACIDS-RICH DIETS SUBJECTED TO PROLONGED PHYSICAL EXERCISE-TRAINING

Rats weighing 45-50 g were fed 3 diets for 8 wk: a balanced control di et (CD) consisting of 4% fat (polyunsaturated/saturated fatty acids [P /S] ratio 2.9/1) and two fat-rich diets: polyunsaturated (UD)-P/S 7.6/ 1 and saturated (SD) P/S 0.3/1. After 8 wk feeding on the respective d iets, rats were subjected to swimming for 90 min at 30 degrees C daily , 5 d/wk for 8 wk. At the end of this period, the rats were killed and the lymphoid organs (LO-thymus, spleen, and mesenteric lymph nodes) a nd muscles (soleus and gastrocnemius) removed for the measurement of T BARs (Thiobarbituric Acid Reactant Substances) content and of the acti vities of antioxidant enzymes (CuZn- and Mn-Superoxide dismutase-SOD-, catalase, and glutathione peroxidase). To evaluate the changes in the sites of generation of reducing equivalents involved in the formation of free radicals, the activities of citrate synthase and glucose-6-ph osphate dehydrogenase were measured. The exercise-training clearly mod ified the enzyme activities and TBARs content of the lymphoid organs a nd skeletal muscles, but this effect was dependent upon the diet given to the rats. However, fatty acid rich diets had presented a more pron ounced effect on the studied aspects than did physical activity. Altho ugh one could expect a summatory effect of polyunsaturated fatty acid- rich diet and exercise-training, swimming increased the activities of CuZn- and Mn-SOD in almost all tissues from the elevated level promote d by fat-rich