The effect of insulin on bile-salt-independent canalicular secretion

Mongrel dogs were prepared by cholecystectomy, ligation of the lesser pancreatic duct, and insertion of gastric and duodenal cannulas. The common bile duct was cannulated through the duodenal fistula. After stabilization of bile flow by intravenous infusion of sodium taurocholate, the dogs received an intravenous injection of insulin or 0.9% NaCl (control). This procedure was repeated with varying concentrations of sodium taurocholate to obtain taurocholate dose-response tests with and without insulin. Insulin caused marked increases in bile flow and the biliary clearance of erythritol, with no increase in bile-salt output The regression of bile-salt output on erythritol clearance was calculated for experiments with and without insulin. The resulting lines were compared by covariate analysis, which revealed a significantly higher intercept during insulin choleresis. This observation demonstrated that insulin stimulated the bile-salt-independent fraction of canalicular bile formation.