Effect of Epinephrine on Insulin Release in Man induced by Secretin

SEVERAL observations taken together support the suggestion that the pancreatic β-cell responds in different ways to an oral glucose meal and to an intravenous infusion of glucose. (1) Oral glucose produces a greater rise in concentrations of plasma insulin than does an identical intravenous load 1,2 ; (2) oral glucose provokes a response in plasma insulin four or five times greater than that achieved by infusing glucose intravenously to comparable concentrations of blood glucose 3 ; (3) epinephrine blunts the release of insulin usually encountered after intravenous infusion of glucose 4 , but fails to suppress the rise in concentrations of plasma insulin which follows an oral glucose meal 5 .