Inhibitory effect of short-term bile duct ligation on hepatic cytochrome P450 of bile acid-depleted rats

In this study we analyzed the effect resulting from a short-term (1 h) bile duct obstruction in bile acid-depleted or taurocholate-replenished rats on liver cytochrome P450 enzyme system activity. Rats were depleted of endoge nous bile acids and then subjected to a biliary obstruction for 1 h. Some o f these depleted-obstructed rats were replenished previously to the obstruc tion with exogenous taurocholic acid (TC) and the others were treated with the solvent alone. To study the isolated effect of the bile acid, other rat s were also previously depleted and then replenished with TC but they were obstructed briefly (20 min). CYP3A2-linked activity was evaluated in vivo w ith the aminopyrine breath test and in vitro by the measurement of nifedipi ne oxidase microsomal activity. The results suggested that bile flow suppre ssion per Be might inhibit this CYP-linked activity and that bile acid rete ntion is not involved at least as a sole determinant. Copyright (C) 2001 S. Karger AG, Basel.