A Physiological Model to Study Gallbladder Function in Primates

Abstract

A primate model employing awake cholecystopexed baboons has been designed to permit quantitative studies of gallbladder function and its influence on the hepatic secretion of bile salts. Duodenal perfusion with [3H]inulin measures total bile salt output into the duodenum, while periodic percutaneous sampling of gallbladder bile labeled with [14C]inulin permits quantitation of changes in volume and bile composition in the gallbladder. The appearance of [14C]inulin in the duodenum quantitates gallbladder emptying. The presence of the catheter does not change the gallbladder’s ability to concentrate either radiographic dye or bile salts, nor does it interfere with or induce contraction. During fasting, hepatic bile salt secretion was low (about 5 mmoles per min) with less than one-half the output entering the gallbladder. No gallbladder contents appeared in the duodenum until contraction was induced by cholecystokinin. However, after gallbladder contraction with mobilization of the bile salt pool, hepatic bile salt secretion increased 2- to 4-fold. The preliminary data suggest that gallbladder filling and emptying play a role in governing the movement of bile salts around the enterohepatic circulation.