Propranolol prevents the development of venous thrombosis in rats by a platelet-dependent mechanism

To clarify if one of the most common antihypertensive drugs, propranolol, can prevent venous thrombotic process, rats were treated with propranolol (PRO; 5 mg/kg i.p.) in an acute or chronic (14 days) manner. Both regimens resulted in a marked reduction of the systolic blood pressure (p < 0.001) and, probably as a consequence, in the shortening of the bleeding time (p < 0.01). After ligation of the vena cava, the incidence of the venous thrombosis and the thrombus weight decreased significantly in both propranolol-treated groups (p < 0.01) when compared to control rats. The antithrombotic effect of PRO was not accompanied by any changes in activated partial thromboplastin time, prothrombin time or euglobulin clot lysis time. However, long-term administfation of PRO resulted in a reduction of the ADP-induced platelet aggregation.