Stimulation of glucagon secretion by arginine and histidine infused intrapancreatically.

Either arginine or histidine dissolved at a concentration of 8 mmoles/kg/1 was administered into the cranial pancreaticoduodenal artery at a rate of 5/6 ml/min to observe any direct effect of these essential l-amino acids on secretion of glucagon and insulin in anesthetized dogs. The infusion of arginine induced a prompt, short-lived and more than 3-fold elevation in plasma immunoreactive glucagon (IRG) concentration and about 6-fold augmentation in plasma immunoreactive insulin (IRI) level in the cranial pancreaticoduodenal vein. Plasma IRI concentration in the femoral artery reflected a delayed significant enhancement, but the peripheral plasma level of IRG failed to show any definite reflection. An equimolar load of histidine also caused an immediate, significant but much smaller elevation in pancreatic effluent plasma levels of both IRG and IRI. No definite rise in plasma IRG and IRI was elicited in the femoral artery upon local infusion of histidine. Blood sugar concentration was significantly raised...