EFFECT OF EXERCISE TRAINING ON THE ONSET OF TYPE-I DIABETES IN THE BBWOR RAT/

The effects of regular exercise training on the onset and/or severity of hyperglycemia were studied in female diabetes-prone Biobreeding/Wor cester (DP BB/Wor) rats. At 38-39 d of age, animals were weight-matche d and randomly assigned to exercise-trained (T) and untrained (Unt) gr oups. The T rats exercised on a rodent treadmill at a moderate workloa d, 5 successive days with the 6th day being one of rest. Training last ed 5-11 wk until rats became moribund. Red gastrocnemius muscle citrat e synthase activity was significantly higher in T (54.2 +/- 4.7 mu mol .g(-1).min(-1)) compared with Unt (42.9 +/- 5.1). No significant diffe rence was found between the T and Unt groups in the following: age at onset of hyperglycemia (T = 82.9 +/- 8.7 d; Unt = 82.0 +/- 13.5 d, (X) over bar +/- SD), ultimate level of hyperglycemia, age of death (T = 89.9 +/- 9.2 d; Unt = 89.4 +/- 13.9 d), number of days between onset o f hyperglycemia and death, or body weights at the onset of hyperglycem ia. No significant difference was found between groups in pancreatic i nsulin concentration (mu.g(-1) of protein), T = 0.22 +/- 0.04; Unt = 0 .20 +/- 0.34. These data suggest that a program of regular exercise tr aining may not delay the onset and/or reduce the severity of hyperglyc emia in the DP BB/Wor rat. Regular exercise training had no beneficial or detrimental effect on pancreatic beta-cell destruction.