PHYSICAL-TRAINING ATTENUATES PHOSPHOCREATINE AND LONG-CHAIN ACYL-COA ALTERATIONS IN DIABETIC RAT-HEART

This study was designed to assess the effect of physical training on h igh-energy phosphate levels in the heart of diabetic rats. Diabetes wa s induced with streptozocin (50 mg/kg), and exercise training was carr ied out on a treadmill with a progressive 10-wk program. Plasma glucos e levels at the end of the training program showed only a small improv ement of the diabetic state in trained animals (21.7 +/- 1.3 vs. 24.4 +/- 0.8 mmol/l; P < 0.05). The lower heart rate observed in sedentary diabetic rats (279 +/- 6 vs. 356 +/- 5 beats/min; P < 0.001) was impro ved bv physical training (301 +/- 8 beats/min; P < 0.05 vs. sedentary diabetics). Significantly lower phosphocreatine levels were found in s edentary diabetic rats (12.0 +/- 0.7 mumol/g dry wt) than in sedentary control rats (15.0 +/- 0.9 mumol/g dry wt; P < 0.05) but not in train ed diabetic rats (13.7 +/- 0.7 mumol/g dry wt). ATP levels were not af fected by diabetes but were increased by training. The increased long- chain acyl-CoA levels in sedentary diabetic rats (146 +/- 7 vs. 119 +/ - 8 mumol/g dry wt in sedentary control rats; P < 0.05) were improved by training (138 +/- 6 mumol/g dry wt; P > 0.05 vs. sedentary control rats). These data indicate that the diminution in phosphocreatine leve ls observed in the heart tissue of chronically diabetic rats can be at tenuated by an exercise training program.