Effects of oxygen supply on electrical and secretory responses of humorally stimulated acinar cells in isolated rat pancreas

Abstract

A technique is described for perfusing isolated rat pancreas with a modified Krebs-Henseleit solution. This preparation made feasible the simultaneous measurement of transmembrane potential, effective membrane resistance, rate of flow of pancreatic juice and amylase output. The hyperpolarizing effect of cholecystokinin-pancreozymin (CCK-PZ) was confirmed by perfusion with a solution containing 5 mU CCK-PZ/ml. The hyperpolarizing efffect of CCK-PZ was enhanced when the pancreas was perfused with an oxygenated solution containing dog erythrocytes. This effect was inhibited by ouabain and anaerobic conditions. It is suggested that the oxidative metabolism supplies energy for a mechanism which is responsible for the hyperpolarizing effect of CCK-PZ. The amylase output and the rate of flow of pancreatic juice were enhanced concurrently under conditions that augumented the hyperpolarizing effect, and they were inhibited under conditions that suppressed the effect. Cellular events in stimulus-secretion coupling in the pancreatic acinar cell are discussed by correlating the electrophysiological responses and the secretory responses under various conditions.