Insulin-enhanced thermogenesis in skeletal muscle after exercise: regulatory factors

Insulin increases O2 consumption by 25-30% in perfused rat muscle following intense exercise. The object of the present study was to characterize further the basis for this finding. Toward this end, O2 consumption was measured in the perfused hindquarter of rats either following a treadmill run or muscle contractions induced by electrical stimulations of the sciatic nerve. The results indicate that the increase in O2 consumption induced by insulin varies with the intensity of exercise, that it is initiated by factors generated locally rather than systemically, and that it is not attenuated by alpha or beta-adrenergic blockade. The results also demonstrated that the increase in O2 consumption is substantially diminished if glucose is not added to the perfusion medium.