Effects of atropine on the action and release of secretin in humans

Abstract

In 2 groups of volunteers, the effects of atropine on pancreatic secretion of bicarbonate, protein and trypsin stimulated by secretin were investigated. Secretin given i.v. in graded doses of 0.03, 0.06 and 0.125 clinical units/kg per h produced significant increases in pancreatic secretion of bicarbonate in a dose-related manner. Pancreatic secretion of bicarbonate and protein was significantly suppressed by i.v. atropine, despite the dose of secretin infused. Intrajejunal perfusion of HCL at a rate of 3.3 mM/h, producing plasma secretin concentration comparable with that of the postprandial state, resulted in significnt increases in the pancreatic secretion of bicarbonate. The increase in the pancreatic secretion of bicarbonate and trypsin was significantly suppressed by atropine. Atropoine did not affect the increase in the plasma secretin concentration produced by jejunal acidification or i.v. secretin. Aapprently, atropine inhibits the pancreatic effect but not the intestinal release of secretin.