Activation of platelets and of fibrinolysis by venous occlusion in healthy volunteers and influence of suloctidil in comparison with placebo

Abstract

The effect of venous occlusion on blood fibrinolytic activity and platelet activation was studied in 10 normal human volunteers. The procedure was used as a model to study the pharmacological effects of 1-(4-isopropylthiophenyl)-2-n-octylaminopropanol (suloctidil, Sulocton) in a double-blind cross-over trial comparing suloctidil 200 mg three times per day versus identical placebo, each given for one week at random, after an initial one-week placebo run-in; blood sampling was done at the end of each period. Statistically significant changes in plasminogen, alpha 2-anti-plasmin, fibrinogen and antithrombin-III were consistently obtained on each occasion and could be ascribed to local haemoconcentration while a much higher increase of plasminogen activator activity occurred. The influence of venous occlusion on plasma beta-thromboglobulin and platelet factor-4 levels was found to be less consistent and under the trial conditions no obvious difference between the regimens studied could be objectified. On the contrary platelet aggregation by collagen was significantly reduced at the end of the suloctidil period.