Activities of APh, gamma-GT, GlDH and GPT and bile acid concentrations in serum after bile duct obstruction and cycloheximide in the rat.

The aim of this study was to investigate the effect of the protein synthesis inhibitor cycloheximide on the serum activities of gamma-Glutamyltransferase, Glutamate dehydrogenase and Glutamate pyruvate transaminase after bile duct obstruction in rats. The results showed that the increase of these enzyme activities after bile duct obstruction is further augmented by cycloheximide. Determinations of total bile acids in serum and liver showed that also the bile acid concentrations rise to a higher level after bile duct obstruction + cycloheximide than after bile duct obstruction alone. It is concluded that the effect of cycloheximide on the serum enzyme activities in extrahepatic cholestasis is produced via an influence on the metabolism of bile acids. This stresses the central role of bile acids for alterations of enzyme activities in extrahepatic cholestasis. Further, the effect of cycloheximide on bile acids after bile duct obstruction has not been reported before.

[The behavior of mixed function oxidases in the liver of the rat on the first day after ligation of the ductus choledochus]. / Das Verhalten der mischfunktionellen Oxidasen in der Leber der Ratte in den ersten Tagen nach Ligatur des 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.