On the mechanism of glucose release from the muscle of juvenile diabetics in acute insulin deficiency.

In fifty-three healthy subjects and twenty-three juvenile diabetics the measurement of arterial and deep venous glucose concentrations showed that the substrate was taken up by the tissues of the forearm of all the healthy subjects and released from it in all the diabetic ones. In six of the diabetics glucose output was accelerated almost five-fold during the intrabrachial arterial administration of metaproterenol (1.62 nmol/min), indicating that basal glucose release from muscle may result from enhanced glycogenolysis during acute insulin deficiency. In line with this view a reduction of glucose uptake by muscle was observed in six healthy subjects receiving metaproterenol infusion. However, since the production of lactate by the forearm appeared to be smaller in the diabetics, the basal glucose output could also partly be due to impaired glycolysis. These data suggest that the glucose released from muscle during acute insulin deficiency may be of clinical importance, especially when the rate of glycogenolysis is further stimulated by, for example, enhanced catecholamine drive.