Ethanol reduces hepatic estrogen-2-hydroxylase activity in the male rat

Andrew R. Hoffman, Edward Majchrowicz, Merrily A. Poth, Steven M. Paul

Research output: Contribution to journalArticlepeer-review

13 Scopus citations


Brief exposure to intoxicating levels of ethanol in the male rat produced a marked reduction in a major hepatic enzyme responsible for estrogen metabolism (estrogen-2-hydroxylase). After 4 days of ethanol administration the specific activity of this enzyme decreased by 70% and remained decreased for 6 days following alcohol withdrawal. Enzyme activity returned to control levels by two weeks. However, if animals were retreated with ethanol for one day each week the enzyme activity remained low. Kinetic analysis of the enzymatic activity from ethanol-treated rats showed a decrease in specific activity (Vmax) with no alteration in substrate affinity (apparent Km). The decrease in enzyme activity persisted long after ethanol disappeared from the blood and concentrations of ethanol from 20-100 mM had no effect on enzyme activity when added in vitro. A similar effect of ethanol on hepatic estrogen metabolism in humans may partially explain the elevated serum estrogen levels and the signs of hyperestrogenization observed in male alcoholic patients.

Original languageEnglish
Pages (from-to)789-794
Number of pages6
JournalLife Sciences
Issue number8
StatePublished - Aug 24 1981


Dive into the research topics of 'Ethanol reduces hepatic estrogen-2-hydroxylase activity in the male rat'. Together they form a unique fingerprint.

Cite this