Yamaguchi T, Wakabayashi Y, Tanaka M, Sano T, Ishikawa H, Nakajima H, Suematsu M, Ishimura Y
Department of Biochemical Genetics, Tokyo Medical and Dental University, Japan.
Am J Physiol. 1996 Jun;270(6 Pt 1):G1028-32. doi: 10.1152/ajpgi.1996.270.6.G1028.
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 enzyme-linked immunosorbent microassay with the use of antibilirubin 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-1.g liver-1), corresponding to 60% of the outflow of CO into the venous effluents. In its absence, however, the total amount of bilirubin excreted into extrahepatic compartments was reduced to 27% of CO flux, and more than 90% of the excreted bilirubin was in the venous effluent. Thus a choleretic bile acid such as taurocholate is necessary for directional transport of bilirubin into bile in the perfused liver preparation.
在离体灌注大鼠肝脏中，研究了门脉血中主要的结合胆汁酸之一牛磺胆酸盐在胆红素从肝实质排泄至胆管和血管腔室中的作用。分别使用抗胆红素单克隆抗体24G7通过酶联免疫吸附微量测定法和肌红蛋白辅助分光光度法测定胆汁或静脉流出液中胆红素和一氧化碳（CO）的含量。在存在牛磺胆酸盐的情况下，排泄到胆管腔室中的胆红素占肝脏排泄的总胆红素（0.26 nmol·min-1·g肝脏-1）的90%以上，相当于流入静脉流出液中的CO的60%。然而，在不存在牛磺胆酸盐的情况下，排泄到肝外腔室中的胆红素总量降至CO通量的27%，并且排泄的胆红素中超过90%存在于静脉流出液中。因此，在灌注肝脏制剂中，牛磺胆酸盐这样的利胆胆汁酸对于胆红素向胆汁中的定向转运是必需的。
