Antithrombotic effect of enalapril, an angiotensin-converting enzyme inhibitor, on venous thrombosis in rats.

The aim of the study was to investigate the potential antithrombotic action of enalapril in comparison with captopril after their acute and chronic administration in an experimental model of venous thrombosis in rats. Chronic treatment with captopril but not enalapril significantly reduced the incidence of venous thrombosis (67% vs 11%; p < 0.05). Both drugs markedly reduced the weight of thrombus. At the same time the platelet aggregation was reduced in rats acutely treated with both captopril and enalapril to 50 +/- 13% and 53 +/- 18%, respectively. The mean blood pressure dropped only after acute ACE-Is administration. No changes were observed in "transection" bleeding time. In conclusion, captopril and enalapril were able to inhibit the growth of thrombus in rats. Their antithrombotic effect seems to be independent from hypotensive action and influence on platelet aggregation.