Effects of exogenous glucagon on pancreatic and biliary ductal and sphincteric pressures in man demonstrated by endoscopic manometry and correlation with plasma glucagon.

An endoscopic manometric technique was used to investigate the effects of glucagon on pancreatic duct, common bile duct, pancreatic duct sphincter, and bile duct sphincter pressures in 20 healthy volunteers. Glucagon was given by intravenous infusion at rates of 0.016, 0.0625, 0.25, 1.0, 4.0, and 16.0 micrograms/kg/hr and also as an intravenous bolus of 1 mg. Plasma glucagon was measured by radioimmunoassay. Glucagon significantly reduced peak bile duct sphincter pressure from 49.1 +/- 3.7 mm Hg (mean +/- SD) to 37.8 +/- 2.9 mm Hg (P less than 0.01) at a rate of 0.016 microgram/kg/hr, reaching a maximum effect at rates of 0.25 microgram/kg/hr and above. Reduction in pancreatic duct sphincter, pancreatic duct, and bile duct pressures; slowing of sphincter wave frequency; and shortening of wave duration occurred at infusion rates of 1.0 microgram/kg/hr or greater when plasma concentrations were supraphysiological. We conclude that glucagon has a physiological action on the bile duct sphincter but that all other effects on this area are pharmacological.