Harmful effect of land-based endurance exercise in rats with diabetic nerve.

PURPOSE: Repetitive limb movements made during aerobic exercises, such as walking and jogging that are frequently prescribed for diabetes control, can induce nerve strain, which has been reported to induce nerve ischemia. Nerves in a diabetic background are more vulnerable to ischemia. We investigated the effects of repetitive treadmill and swimming exercises on nerves in diabetic rats.

METHODS

Rats with diabetic neuropathy were randomly allocated to one of three groups, namely, control (n = 7), treadmill (n = 8), and swimming (n = 8) groups. After 12 wk of exercise, sural and sciatic nerves were harvested and analyzed by Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and Western blotting.

RESULTS

In sural nerves, percentages of TUNEL-positive cells and BAX/GAPDH level were higher in the treadmill than that in the swimming group. In sciatic nerves, there was no significant difference among three groups.

CONCLUSIONS

: Endurance exercises increase Schwann cell apoptosis in distal peripheral nerves. Greater loadings during exercise were found to increase Schwann cell apoptosis. Land-based endurance exercises may have a harmful effect on peripheral nerves in certain individuals with diabetes.