Monooxygenase activity of fish liver in biomonitoring aquatic environment.

The hepatic biotransformation activity of four cultivated freshwater fish, Amur carp (Ctenopharyngodon idella), carp (Cyprinus carpio), rainbow trout (Salmo gairdneri) and tench (Tinca tinca) were studied one day after catching the fish from ponds and a river in the south of GDR and in fish kept for two weeks in clean filtrated and deacidified water. Aryl hydrocarbon hydroxylase, 7-ethoxycoumarin O-deethylase and 7-ethoxyresorufin O-deethylase activities fell to about 20% during the stay in clean water in rainbow trout liver microsomes. The reductions were smaller in the other species studied.