Effects of β-naphthoflavone on hepatic biotransformation and glutathione biosynthesis in largemouth bass ( Micropterus salmoides)
We are investigating the effects of in vivo exposure of prototypical enzyme inducing agents on hepatic biotransformation enzyme expression in largemouth bass ( Micropterus salmoides), a predatory game fish found throughout the United States and Canada. The current study targeted those genes involved...
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Veröffentlicht in: | Marine environmental research 2004-08, Vol.58 (2), p.675-679 |
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Sprache: | eng |
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Zusammenfassung: | We are investigating the effects of in vivo exposure of prototypical enzyme inducing agents on hepatic biotransformation enzyme expression in largemouth bass (
Micropterus salmoides), a predatory game fish found throughout the United States and Canada. The current study targeted those genes involved in biotransformation and oxidative stress that may be regulated by Ah-receptor-dependent pathways. Exposure of bass to β-naphthoflavone (β-NF, 66 mg/kg, i.p.) elicited a 7–9-fold increase in hepatic microsomal cytochrome P4501A-dependent ethoxyresorufin O-deethylase (EROD) activities, but did not affect cytosolic GST catalytic activities toward 1-chloro-2,4-dinitrobenzene (CDNB) or 5-androstene-3,17-dione (ADI). Glutathione S-transferase A (GST-A) mRNA expression exhibited a transient, but non-significant increase following exposure to β-NF, and generally tracked the minimal changes observed in GST–CDNB activities. Expression of the mRNA encoding glutamate-cysteine ligase catalytic subunit (GCLC), the rate-limiting enzyme in glutathione (GSH) biosynthesis, was increased 1.7-fold by β-NF. Changes in GCLC mRNA expression were paralleled by increases in intracellular GSH. In summary, largemouth bass hepatic CYP1A-dependent and GSH biosynthetic pathways, and to a lesser extent GST, are responsive to exposure to β-NF. |
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ISSN: | 0141-1136 1879-0291 |
DOI: | 10.1016/j.marenvres.2004.03.061 |