Taurocholate induces directional excretion of bilirubin into biles in the perfused rat liver. Yamaguchi, Tokio, Yoshiyuki Wakabayashi, Makiko Tanaka, Tsuyoshi Sano, Hiromi Ishikawa, Hiroshi Nakajima, Makoto Suematsu, Yuzuru Ishimura. Department of Biochemical Genetics, Medical Research Institute, Tokyo Medical and Dental University, Tokyo 113, Department of Biochemistry, School of Medicine, Keio University, Tokyo 160, Japan
APStracts 3:0034G, 1996.
The role of taurocholate, one of the major conjugated bile acids present in portal blood in excretion of bilirubin from liver parenchyma to biliary and vascular compartments was studied in isolated perfused rat liver. Contents of bilirubin and carbon monoxide (CO) in the bile or venous effluents were determined by an enzyme-linked immunosorbent microassay using an anti-bilirubin monoclonal antibody 24G7 and myoglobin-assisted spectrophotometry, respectively. In the presence of taurocholate, bilirubin excreted into the biliary compartment constituted greater than 90% of the total bilirubin excreted from the liver (0.26 nmol / min / g liver) corresponding to 60% of the outflow of CO into the venous effluents. In its absence, however, total amount of bilirubin excreted into extrahepatic compartments was reduced to 27% of the CO flux, and more than 90% of the excreted bilirubin was in the venous effluent. Thus, a choleretic bile acid such as taurocholte is necessary for directional transport of bilirubin into biles in the perfused liver preparation.

Received 30 October 1995; accepted in final form 25 January 1996.
APS Manuscript Number G470-5.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 8 February 96