EFFECTS OF TRAINING AND DIETARY GLUTATHIONE ON LIVER AND MUSCLE GLUTATHIONE STATUS IN RATS

Abstract

71 The purpose of the present study was to investigate the effects of endurance training (T) in conjunction with glutathione (GSH) supplementation (S) on liver and muscle GSH status in rats. Forty female Sprague-Dawley rats (age 4 mo.) were randomly divided into either untrained (U) or T (treadmill running at 25 m/min, 15% grade for 75 min/day, 5 d/wk for 10 wk). Half of U and T group of rats was fed a GSH-S diet (5g GSH/kg) during the final 17 days of training, whereas the other half received control (C) diet. Liver and muscle tissues were removed immediately after an open-heart sham surgery lasting 90 min performed 52 h after the last training session. GSH and glutathione disulfide (GSSG) contents were measured in liver, soleus (SOL), and deep (DVL) and superficial (SVL) vastus lateralis muscles using HPLC method. T increased citrate synthase activity in SOL by 50 and 47% (P<0.01) in C and GSH-S, respectively. Liver GSH content was increased by 9% with T (P<0.05), by 9% with GSH-S (P<0.05), and by 17% with T plus GSH-S (P<0.05). GSSG content was increased by 15 and 8% with T (P<0.05) in C and GSH-S, respectively. Thus, in U rats the GSH:GSSG ratio was elevated by 24% in GSH-S vs. C (P<0.05). GSH content in SOL decreased by 32 and 30% with T (P<0.05) in C and GSH-S, respectively, whereas GSSG level was unaltered. These changes resulted in a 26 and 23% lower GSH:GSSG ratio with T in C and GSH-S rats, respectively. Neither T nor GSH-S affected GSH and GSSG content in DVL and SVL. In conclusion, endurance training in conjunction with GSH-S improved post-surgical GSH content and redox status in the liver. GSH-S in the current regimen did not increase muscle GSH status or prevent the exercise-induced decrease in GSH content in the soleus. (Supported by AHA-WI grant-in-aid and CNPq-Brazil)