Response of xenobiotic metabolizing enzymes of rainbow trout (Oncorhynchus mykiss) to the mono-ortho substituted polychlorinated PCB congener 2,3',4,4',5-pentachlorobiphenyl, PCB-118, detected by enzyme activities and immunochemical methods.
The mono-ortho-substituted polychlorinated PCB congener 2,3',4,4',5'-pentachlorobiphenyl (PCB-118) was administered i.p. (30 mg/kg body weight) to gonadally immature rainbow trout (Oncorhynchus mykiss), of both sexes. In liver microsomes prepared from fish killed 4 days after administration, the cytochrome P450-dependent monooxygenase activities of 7-ethoxyresorufin O-deethylase (EROD), aryl hydrocarbon hydroxylase (AHH), and aldrin epoxidase (AE) were measured. In addition, NADPH-cytochrome c reductase (NCCR) was analyzed, and the content of a specific cytochrome P450 isozyme was determined with Western blotting and an enzyme-linked immunosorbent assay (ELISA) using rabbit anticod P450IA1 IgG. The monooxygenase parameters EROD and AHH were significantly induced to 558 and 268%, respectively, of the corresponding control values, while NCCR and AE activities were not affected. The antibodies to cod P450IA1 recognized a single protein band (Mr = 58,000 D) in the rainbow trout liver microsomes. The ELISA absorbance of this protein in the PCB-118 treated fish was 401% of the corresponding value in the controls. These results demonstrate that PCB-118 is an effective inducer of the subfamily cytochrome P450IA1 in rainbow trout liver microsomes.
Skaare
J U
JU
Department of Pharmacology and Toxicology, Norwegian College of Veterinary Medicine/National Veterinary Institute, Oslo.
Jensen
E G
EG
Goksøyr
A
A
Egaas
E
E
D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000096:biosynthesis; D015153:Blotting, Western; D019363:Cytochrome P-450 CYP1A1; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis; D004790:Enzyme Induction; D004797:Enzyme-Linked Immunosorbent Assay; D007120:Immunochemistry; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology*; D006899:Mixed Function Oxygenases / Q000096:biosynthesis; D010088:Oxidoreductases / Q000096:biosynthesis; D011078:Polychlorinated Biphenyls / Q000633:toxicity*; D014337:Trout / Q000378:metabolism*
C070055:2,3',4,4',5-pentachlorobiphenyl; D003577:Cytochrome P-450 Enzyme System; D011078:Polychlorinated Biphenyls; D006899:Mixed Function Oxygenases; D010088:Oxidoreductases; C019647:aldrin epoxidase; D001189:Aryl Hydrocarbon Hydroxylases; D019363:Cytochrome P-450 CYP1A1