Effect of Morphine, Cholecystokinin and Sympathomimetics on the Sphincter of Oddi and Intramural Pressure in Cat Duodenum

Abstract

Intramural pressure in the cat duodenum has been recorded by perfusion of pieces of femoral vein introduced through the duodenal wall. Simultaneously, passage pressure through the sphincter of Oddi and intraluminal pressure in the duodenum were recorded. Morphine increases all pressures. Noradrenaline inhibits intestinal activity but contracts the sphincter of Oddi. β-Adrenoceptor-stimulating agents decrease all pressures. Cholecystokinin relaxes the sphincter of Oddi and also the duodenum surrounding the sphincter but tends to contract more distal parts of duodenum. Given together with morphine the qualitative effects of these agents are the same. Combination of morphine and noradrenaline shows that morphine induces contraction of the muscle of the sphincter of Oddi as well as of the intestine.