Effects of ethanol on conjugated gonadal hormones in plasma of men

The effects of ethanol, 0.3 g/kg body weight, on the concentrations of testosterone, androsterone, estradiol and estrone in unconjugated as well as conjugated forms in plasma of men were analyzed by gas chromatography-mass spectrometry using labelled internal standards. The concentrations of unconjugated steroids remained unchanged while the concentrations of estradiol conjugates increased markedly in all subjects in parallel with the alcohol concentration in blood. The results indicate that the reduction of the 17-oxo group of estrogen conjugates is influenced by the altered redox state in the liver during ethanol oxidation. The increased formation of estradiol conjugates combined with their hydrolysis in target organs could be one of the mechanisms behind the feminizing effects of ethanol.