Canalicular bile production in dogs.

WHEELERJENRY ~.,ELIZABETH D.Ross, AND STANLEY E. BRADLEY. Canalicular bile production in dogs. Am. J. Physiol. 2 14(4) : 866-874. 1968.-Biliary clearances of 14C-labeled creatinine, erythritol, inulin, mannitol, sucrose, and urea were measured in three unanesthetized cholecystectomized dogs equipped with Thomas duodenal cannulas. Sodium taurocholate was infused intravenously at varying rates to produce changes in bile flow. Clearance of mannitol varied linearly with bile acid secretion rate and in most cases was higher than bile flow. Clearances of creatinine, erythritol, and urea were similar to mannitol clearance except that erythritol clearance was slightly higher than mannitol clearance in one of the three dogs. Bile-to-plasma concentration ratios were usually greater than one and were highest at low rates of bile acid secretion. Inulin and sucrose clearances were very low. Secretin choleresis had no effect on mannitol clearance. These data suggest that clearances of compounds such as mannitol and erythritol provide an estimate of canalicular bile flow in the dog. While canalicular flow is linearly related to bile acid secretion rate, there appears to be an independent basal rate of canalicular bile production. Canalicular bile is concentrated as much as threefold by ductal or ductular fluid reabsorption in the dog.