Induction of cytochrome P450 1A1 and conjugating enzymes in rainbow trout (Oncorhynchus mykiss) liver: A time course study

Citation

Celander M, Leaver M, George S & Forlin L (1993) Induction of cytochrome P450 1A1 and conjugating enzymes in rainbow trout (Oncorhynchus mykiss) liver: A time course study. Comparative Biochemistry and Physiology - Part C: Pharmacology, Toxicology and Endocrinology, 106 (2), pp. 343-349. http://www.sciencedirect.com/science/article/pii/074284139390144A; https://doi.org/10.1016/0742-8413%2893%2990144-A

Abstract
1. The effects of i.p. injections of isosafrole (ISF) or β-naphthoflavone (β-NF) on the cytochromeP450 (CYP) 1A1 system and conjugatingenzymes were investigated in livers from juvenile rainbowtrout in atimecoursestudy employing catalytic, immunochemical and cDNA probes. 2. β-NF treatment resulted in a rapid rise in CYP1A1 mRNA followed by accumulation of P4501A1 protein and P4501A1 mediated enzyme activity measured as ethoxyresorufin-O-deethylase (EROD) activity. 3. ISF treatment resulted in a comparatively weak induction of CYP1A1 mRNA and P4501A1 protein levels whilst EROD activity was markedly induced; thus when expressed on the basis of immunoquantified P4501A1 protein, the specific EROD activity was signficantly higher in ISF than β-NF treated fish. 4. In vitro inhibition studies revealed that ISF inhibited EROD activity to a far lesser extent than β-NF. 5. Conjugation enzymes represented by phenol UDP-glucuronosyltransferase and glutathione S-transferase (GST) activities, were induced by β-NF, whereas ISF treatment had no effect on these enzyme activities. 6. Immunoblotting using antibodies raised against rat GST7-7 showed that a Pi class trout GST enzyme was induced by β-NF treatment.

Journal
Comparative Biochemistry and Physiology - Part C: Pharmacology, Toxicology and Endocrinology: Volume 106, Issue 2