Induction of aryl hydrocarbon hydroxylase activity in the rat prostate glands by 2,3,7,8-tetrachlorodibenzo-p-dioxin.
Because of the interest in male reproductive tract toxicity, we determined the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on cytochrome P-450 levels and the specific activity of aryl hydrocarbon hydroxylase (AHH), epoxide hydrase and glutathione S-transferase in the rat prostate glands after a single oral dose of TCDD (10 microgram/kg b.wt.). The maximum induction of AHH activity and cytochrome P-450 levels in the prostate glands was approximately 200- and 6.5-fold that of controls. After TCDD treatment, the peak induction of AHH activity and cytochrome P-450 levels in the prostate glands was observed at 16 and 48 hr, respectively; however, the specific activity of epoxide hydrase or glutathione S-transferase in prostate glands was not induced at any time after TCDD treatment. TCDD-induction of AHH and cytochrome P-450 contents can be completely inhibited by a single pretreatment with either actinomycin D or cycloheximide, suggesting TCDD induces de novo synthesis of specific proteins. Dramatic increases in AHH activity (200-fold increase) were associated with the new formation of cytochrome P-450 in the rat prostate glands after a single oral dose of TCDD. The biological significance of such a dramatic increase of prostatic AHH activity and the emergence of new cytochrome P-446 in rat prostate glands is unknown at the present time.
D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000096:biosynthesis*; D003513:Cycloheximide / Q000494:pharmacology; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis; D003609:Dactinomycin / Q000494:pharmacology; D004147:Dioxins / Q000633:toxicity*; D004790:Enzyme Induction; D008297:Male; D000072317:Polychlorinated Dibenzodioxins / Q000633:toxicity*; D011467:Prostate / Q000187:drug effects / Q000201:enzymology*; D051381:Rats; D013997:Time Factors
D004147:Dioxins; D000072317:Polychlorinated Dibenzodioxins; D003609:Dactinomycin; D003577:Cytochrome P-450 Enzyme System; D003513:Cycloheximide; D001189:Aryl Hydrocarbon Hydroxylases