INFLUENCE OF ETHANOL AND SEROTONIN ON RAT PLATELET-AGGREGATION

We demonstrated that ethanol (1.0, 2.0 and 4.0 g/kg p.o.) significantly decreased blood platelet aggregation in a dose-dependent manner. The chronic administration of ethanol (6 g/kg daily for 4 weeks) also altered the sensitivity of rat platelets to ADP (4 μmol/l). We found that the acute and chronic administration of alcohol significantly increased the amplifying effect of 5-hydroxytryptamine (5-HT; 10-6 mol/l) on ADP-induced aggregation. In all groups of rats, ketanserin (10-5 mol/l) compledtely inhibited the amplification of aggregation induced by serotonin. In conclusion, the present results show that ethanol did not only produce inhibition of ADP-induced platelet aggregation but also affected the potentiating action of 5-HT on this process.