Insulin‐stimulated bile formation in cats

Abstract

Abstract The effects of insulin on bile flow and composition were examined in fasting, chloralose‐anesthetized cats. Insulin in doses from 0.01 to 2.00 U/kg increased bile flow and biliary erythritol clearance without any detectable change in the difference between them; thus insulin presumably had no effect on ductular fluid transport. Continuous infusion of insulin (0.8 U/kg + 0.05 U/kg/min or 0.05 Uykg + 0.002 U/kg/min) increased biliary erythritol clearance by 22%. The increase was caused by a rise in the bile acid‐independent fraction of bile production and accompanied by a parallel increase in the rates of biliary excretion of Na + and Cl ‐ . When ouabain, 80 μg/kg, was injected intraportally during insulin infusion the erythritol clearance, bile flow and the rates of biliary excretion of Na + and Cl ‐ were lowered towards but not to their pre‐ insulin levels. The effects of insulin on these parameters were unchanged after atropin or gastrectomy and 2‐Deoxy‐D‐Glucose was without effect on bile production. The results indicate that administration of insulin affects bile formation by stimulating the active transport of sodium across the canalicular membrane.