Effect of hypophysectomy and growth hormone replacement on the modulation of p450 expression after treatment with the aromatic hydrocarbon ethylbenzene

Toxicology and Applied Pharmacology
S C SerronW L Backes

Abstract

Pituitary status has a significant effect on the expression of several cytochrome P450 enzymes. The goal of this study was to examine the role of pituitary input on the modulation of CYP2C11 and CYP2B after treatment with the aromatic hydrocarbon ethylbenzene (EB). Intact, hypophysectomized (HX), and HX rats supplemented with pulsatile growth hormone (GH) were treated with corn oil or EB and the effects on hepatic P450 expression were determined. Hypophysectomy caused a 50% decrease in CYP2C11 protein in untreated rats, whereas GH supplementation returned protein to control levels. EB administration also decreased CYP2C11 protein in intact rats; however, this decrease was not observed after EB treatment in HX or HX + GH groups. CYP2C11-dependent testosterone 2alpha-hydroxylation followed a similar pattern as CYP2C11 protein, except that the activity was only partially restored by GH replacement. CYP2B levels were also substantially influenced by hypophysectomy. Intact rats exhibited a 100-fold increase in CYP2B1 mRNA, reaching a maximum 12 h after EB administration. A much smaller response (ca. 20-fold) was observed in HX rats, reaching a maximum 24 h after EB treatment. This effect was not reversed by GH supplementation. The h...Continue Reading

References

Sep 25, 1992·Biochemical Pharmacology·D J SequeiraW L Backes
Jan 1, 1992·Advances in Enzyme Regulation·A ModeJ A Gustafsson
Feb 1, 1992·The Biochemical Journal·D J Waxman, L Azaroff
Feb 1, 1992·Journal of Applied Toxicology : JAT·R von Burg
Aug 1, 1991·Proceedings of the National Academy of Sciences of the United States of America·D J WaxmanB H Shapiro
Jan 1, 1995·Xenobiotica; the Fate of Foreign Compounds in Biological Systems·W YuanW L Backes
Feb 1, 1994·Fundamental and Applied Toxicology : Official Journal of the Society of Toxicology·J S Tegeris, R L Balster
Aug 17, 1994·Biochimica Et Biophysica Acta·D J SequeiraW L Backes
Dec 1, 1993·Xenobiotica; the Fate of Foreign Compounds in Biological Systems·W L BackesC S Eyer
Mar 24, 1993·Molecular and Cellular Biochemistry·A V HodgsonH W Strobel
May 9, 1998·Xenobiotica; the Fate of Foreign Compounds in Biological Systems·R M BergeronW L Backes

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Citations

Mar 9, 2002·Toxicology and Applied Pharmacology·Shuxin ZhangWayne L Backes
Jun 6, 2008·Drug Metabolism and Disposition : the Biological Fate of Chemicals·Rana M Sawaya, David S Riddick
Mar 25, 2004·Drug Metabolism and Disposition : the Biological Fate of Chemicals·David S RiddickJohn Y L Chiang

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