The effects of exercise on the metabolic fate of glucose in the adipocyte of female rats
This study examined the effects of exercise on glucose metabolism in adipocytes from female rats. Female rats were exercised by swimming six hours per day, five days per week for eight weeks. There was no variation in body weight gain (P > 0.05) between the exercise and control animals through the experimental period. The swimmers' fat cells were smaller (P < 0.05) than those of the sedentary controls of the same age. The rates of glucose oxidation of both C-1 and C-6 glucose were significantly higher (P < 0.05) in the exercise rats' adipocytes at all insulin concentrations. The sedentary control rats' adipocytes showed no significant response at any insulin concentration. Thus, exercise is a significant stimulus to cause increased oxidation rates in the adipocytes from exercising rats. These data also indicate that glucose transport, not defective glucose oxidation, is the limiting mechanism that accounts for the decreased responsiveness of adipocytes from sedentary control animals.