Effect of acute ethanol intake on thromboxane and prostacyclin in human

To investigate the effects of acute ethanol administration on the production of proaggregatory thromboxane A₂ (TxA₂) and anti-aggregatory prostacyclin (PGI₂), ethanol (1.5 g/kilogram body weight) was given to eight healthy nonsmoking men, and the stable metabolites thromboxane B₂ (TxB₂) and 6-keto-prostaglandin F_1α (6-keto-PGF_1α), respectively, measured by radioimmunoassay from serial blood samples before drinking and during the ensuing 18 hours. Each subject was studied as his own control on another occasion when only an equivalent volume of water was given. Serum TxB₂ level decreased (p < 0.01) from 206 + 31 ng/ml (mean) ± S.E. to 167² ± 24 and 161 ± 23 ng/ml (two and four hours after beginning of the drinking, respectively) concomitantly with the attainment of maximal blood ethanol concentrations (about 120 mg/100 ml), whereas no changes occurred in plasma 6-keto-PGF_1α concentrations. Our results may provide an explanation for known effects of ethanol on platelet aggregation. They also raise speculation whether TxA₂-inhibition and the antiatherogenic effect of alcohol intake are somehow related.