Mixed-function oxygenase in juvenile rainbow trout exposed to hexachlorobenzene or 3,3',4,4'-tetrachlorobiphenyl.
1. 3,3',4,4'-tetrachlorobiphenyl (PCB 77), but not hexachlorobenzene, induced liver microsomal cytochrome P-450 (Cyt P-450), ethoxycoumarin-O-deethylase (ECOD) and ethoxyresorufin-O-deethylase (EROD) in rainbow trout. Maximum induction was observed in a PCB 77 injected group of fish (1.0 mg/kg, i.p. injection) 13 days after the injections being 2, 10 and 50 times the value of non-induced fish, respectively. 2. The apparent Km value of ethoxyresorufin of this induced group of fish differed only slightly from that of non-induced fish. The apparent Vmax value (EROD) was 50 times higher. 3. Freezing small pieces of liver in liquid nitrogen did not produce cytochrome P-420. 4. Fluorimetric and spectrophotometric measurements of EROD correlated.
Tyle
H
H
National Agency of Environmental Protection, Copenhagen, Denmark.
Egsmose
M
M
Harrit
N
N
D000818:Animals; D004790:Enzyme Induction / Q000187:drug effects; D006581:Hexachlorobenzene / Q000633:toxicity*; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology; D006899:Mixed Function Oxygenases / Q000096:biosynthesis / Q000187:drug effects*; D011078:Polychlorinated Biphenyls / Q000633:toxicity*; D014337:Trout / Q000378:metabolism*
D006581:Hexachlorobenzene; D011078:Polychlorinated Biphenyls; D006899:Mixed Function Oxygenases; C028451:3,4,3',4'-tetrachlorobiphenyl