Abstract

The effects of a moderate exercise program on several body parameters and on adipocyte metabolic functions were studied in male rats trained to run on a treadmill. At the end of a 12-wk program no significant changes in body weight, food consumption, or the weight of several organs (liver, kidneys, spleen, testes) were observed in trained rats as compared to sedentary animals. The trained rats, however, presented a slight decrease in weight of the epididymal fat pads which was due to a minor change in adipocyte size, withoutany change in adipocyte number. In spite of these minimal effects on adipocytemorphology, exercise training affected several parameters of adipocyte metabolism - it significantly reduced basal lipolysis per cell (P<0.05) and basal glucose metabolism to CO2 and triglyceride (P<0.02) - the insulin effect on stimulation of glucose metabolism was unchanged, whereas the epinephrine effect on it was reduced (P<0.001)- epinephrine produced a significantly greater (P<0.05) acceleration of lipolysis- the intracellular free fatty acid levels were higher (P<0.025) in the basal state and also after insulin and epinephrine (P<0.05 for both). These findings indicate that exercise training in animals leads to modifications of adipocyte metabolism and hormonal responsiveness even when a modest degree of exercise, unable to affect body weight or adipocyte morphology, is applied. Verf.-Referat