Hepatic estrogen receptors and alcohol intake

Human liver contains estrogen receptors (ER) which render it sensitive to estrogen. Chronic ethanol ingestion in humans and rats results in alterations of circulating sex steroid levels and expression of sex hormone-dependent phenotype. The analysis and quantitation of hepatic estrogen receptor (ER) activity and sex hormone-responsive proteins have been performed over the past two decades. Alcohol abuse appears to induce an increase in ER content of human liver, especially in patients with alcoholic hepatitis actively drinking. This observation is reproduced in an experimental model of chronic alcohol feeding of rats. In male rat liver, the increased ER expression induced by alcohol is associated with an elevated proliferation rate of the hepatocytes. In female liver, the ER content is not affected by alcohol intake and apoptosis prevails over proliferation. The feminization of the liver in males may protect the liver from the severe alcohol-induced liver injury seen in females.