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Effect of xenoestrogen exposure on the expression of cytochrome P450 isoforms in rainbow trout liver
Author(s) -
Katchamart Sirinmas,
Miranda Cristobal L.,
Henderson Marilyn C.,
Pereira Clifford B.,
Buhler Donald R.
Publication year - 2002
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620211125
Subject(s) - vitellogenin , rainbow trout , methoxychlor , cytochrome p450 , medicine , biochanin a , endocrinology , diethylstilbestrol , xenoestrogen , chemistry , trout , cyp3a , estrogen , biology , metabolism , biochemistry , estrogen receptor , genistein , fish <actinopterygii> , daidzein , cancer , pesticide , breast cancer , agronomy , fishery , gene
We studied the estrogenic effects of model chemicals in one‐year‐old juvenile rainbow trout. Methoxychlor (20 mg/kg), diethylstilbestrol (15 mg/kg), 4‐ tert ‐octylphenol (25 and 50 mg/kg), and biochanin A (25 and 50 mg/kg) were injected intraperitoneally on days 1, 4, and 7. Fish were sacrificed on day 9 and examined for multiple biomarkers. All of the test chemicals caused increases in plasma vitellogenin levels, a biomarker of estrogenicity. Treatment with the xenoestrogens decreased hepatic lauric acid hydroxylase activity and, as shown by Western blots, also generally reduced expression of hepatic cytochrome P450s 2K1 (CYP2K1), 2M1 (CYP2M1), and 3A27 (CYP3A27) at the protein level. Both doses of biochanin A also significantly induced P4501A (CYP1A) and greatly increased hepatic 7‐ethoxyresorufin‐O‐deethylase (EROD) activity. These findings suggest that methoxychlor, diethylstilbestrol, 4‐ tert ‐octylphenol, and biochanin A were all estrogenic and mimicked 17b‐estradiol (E2) in repressing the expression of cytochrome P450 isoforms (CYP2K1, CYP2M1, and CYP3A27) in the rainbow trout liver. Additionally, biochanin A was found to induce CYP1A in this fish species.