[The behavior of mixed function oxidases in the liver of the rat on the first day after ligation of the ductus choledochus].

The aim of this study was to investigate the activity of the mixed function oxidases in the liver of the rat during the first days of extrahepatic cholestasis. In particular, contradictory results of previous studies of the metabolism of type I- and type II-substrates should be examined. The activities of the aminopyrine demethylase, aniline hydroxylase and nitroanisole-O-desalkylase were measured in the liver microsomes after sham operation and on the first and third day after ligature of the common bile duct. On the first day of cholestasis both the metabolism of the type I-substrate (aminopyrine) and of the type II-substrates (aniline, nitroanisole) was significantly reduced. On the third day the metabolism of type II-substrates reached nearly normal levels, whereas the metabolism of aminopyrine was even further reduced. Contradictory results of previous studies seem to be due to different times of measurement.