CONCISE PUBLICATION Influence of Physiologic Hyperglucagonemia on Basal and Insulin-Inhibited

hyperglucagonemia on splanchnic glucose output, gluca-gon was infused in a dose of 3 ng/kg per min to healthy subjects in the basal state and after splanchnic glucose output had been inhibited by an infusion of glucose (2 mg/kg per min). In the basal state, infusion of glucagon causing a 309±25 pg/ml rise in plasma concentration was accom-panied by a rapid increase in splanchnic glucose output to values two to three times basal by 7-15 min. The rise in arterial blood glucose (0.5-1.5 mM) correlated directly with the increment in splanchnic glucose out-put. Despite continued glucagon infusion, and in the face of stable insulin levels, splanchnic glucose output declined after 22 min, returning to basal levels by 30-45 min. In the subjects initially receiving the glucose infusion, arterial insulin concentration rose by 5-12 /U/ml, while splanchnic glucose output fell by 85-100%. Infusion of glucagon causing an increment in plasma glucagon con-centration of 272±30 pg/ml reversed the inhibition in splanchnic glucose production within 5 min. Splanchnic glucose output reached a peak increment 60 % above basal levels at 10 min, and subsequently declined to levels 20-25 % below basal at 3045 min. Received for publication 5 May 1976 and in revised for