Influences of Exercise on Neuropathy in Streptozotocin-Induced Diabetic Rats

초록

Objectives: Exercise has been accepted as an important component in improving blood sugar control. The patients with diabetes may give many benefits, such as weight loss, decreased cardiovascular risk factor, improved quality of life, from regular physical exercise. However, there may be several hazards from exercise as well, for example, transient hypoglycemia, arrhythmia, myocardial infarction or sudden death. This study was performed to evaluate the effects of early regular exercise, the electrophysiological and histopathological findings of rat tail nerve in relation to the duration of swimming exercise in rats with diabetic neuropathy. Methods: We used 70 Sprague-Dawley male rats. Diabetes was induced by intraperitoneal injection of STZ (65mg/kg). Blood glucose concentrations were measured in tail vein. One week after injection, seventy rats were divided into 2 groups: experimental 60, normal control 10. The experimental group was divided into 6 subgroups according to whether or not insulin treatment and swimming exercise. Sensory and motor nerve conduction studies were done using in rat tail nerve from beginning and every weekly till to 13th week. Swimming exercise was done for 30 minutes a day, 5 days a week for 13 weeks. Exercise was performed in group 3, 4. Seventh weeks later, exercise was done in group 5, 6 additionally. The structural effect on diabetic neuropathy was assessed by morphometry and ultrastructural examination of rat tail nerve fiber at 14th week. Results: There were significant differences of blood glucose level, body weight, sensory nerve latency and amplitude, motor nerve latency between the diabetic control group, insulin treated group and insulin untreated group. Exercise revealed significant effect in insulin treated groups, but not revealed in insulin untreated groups. Sensory nerve conduction study revealed significantly prolonged latency and decreased amplitude in group 1, 3, 6. Group 5 showed more delayed latency and decreased