Effect of Chronic Ethanol Feeding on Bile Formation and Secretion of Lipids in the Rat

Abstract

To determine the effect of ethanol on composition and formation of bile, male Sprague-Dawley rats were pair-fed a liquid formula diet for 4 weeks containing 36% of calories as either ethanol or Dextri-Maltose. Canalicular flow was estimated by determining the biliary clearance of 14C-erythritol. Following bile duct cannulation, bile was collected immediately before and during infusions of sodium taurocholate (40 μmoles per hr) and analyzed for bile salts, lecithin, and cholesterol. Alcohol-fed rats developed an increase in liver weight (10.3 ± 2.5 versus 8.3 ± 1.2 g), augmented 2-hr bile volumes (2.47 ± 0.52 versus 1.95 ± 0.19 ml), and a greater rate of bile salt secretion both before (608 ± 257 versus 470 ± 154 mμmoles per min) and after (870 ± 150 versus 660 ± 130 mμmoles per min) the infusion of sodium taurocholate. Bile was formed predominantly from the canaliculus in both groups. Hepatic triglyceride levels were increased in rats fed alcohol and each developed microscopic evidence of fatty infiltration of the liver. Nevertheless, ethanol feeding neither altered the bile phospholipid-cholesterol ratio, nor the relative proportions of biliary cholesterol, lecithin, and bile salts. Thus, despite producing abnormalities in hepatic lipid metabolism, chronic ethanol administration was associated with an increase in bile formation and bile salt secretion and did not induce a lithogenic bile in the rat.