Biliary excretion of inulin, sucrose, and mannitol: analysis of bile formation

Abstract

The transfer between blood and bile of three large, inert, water-soluble molecules was investigated in the rat. At the steady state, the bile:plasma concentration ratios were: inulin, 0.1; sucrose, 0.2; and mannitol, 1.2. Since these substances invade substantial hepatic spaces, 24–72% of the wet tissue weight depending on the size of the molecule, the permeability to large, lipid-insoluble molecules appears to be a feature of the hepatic parenchymal cell membrane. Kinetic analysis of the steady-state distribution of sucrose between liver, bile and plasma suggests that two boundaries of the hepatic parenchymal cell, the one which separates the cell interior from plasma, and the one which separates the cell interior from bile, may be equally permeable to sucrose.