Abstract

The effects of insulin and exercise on glucose uptake of skeletal muscle were investigated in soleus muscle isolated from low dose streptozotocin induced diabetic rat in vitro. Glucose uptake was assessed by measuring ³H-methylglucose uptake in vitro. Basal glucose uptake in diabetes was reduced by approximately one-third of the control value (5.6±0.73µMol/g/20min. in diabetes versus 8.4±0.77 in control, P<0.01). There was also a significant decrease (P<0.01) in glucose uptake of diabetes at physiologic insulin concentration (200 µIU/ml) by 40% (6.1±1.20 versus 10.0±0.81). Furthermore, maximal insulin (20000 µIU/ml)-stimulated glucose uptake was 36% lower in diabetes as compared with control (7.3±1.29 versus 11.4±1.29, P<0.01). In contrast, exercise (1.0 km/hr, treadmill running for 45 min.) effect on glucose uptake was so dramatic in diabetes that glucose uptake at basal state was 8.+1.09 and insulin stimulated-glucose uptake were 10.2±1.47 and 11.9±1.64, in 200 and 20000 µIU/ml added insulin, respectively. These results suggest that insulin insensitivity develops in skeletal muscle after 2 weeks of streptozotocin-induced diabetes, but these insensitivity was recovered significantly by single session of running exercise.

• Keywords: streptozotocin induced diabetes;glucose uptake;rat soleus muscle;