[Comparative effect of chlorpromazine, imipramine and papaverine on the blood platelet function].

With a view of decoding the mechanisms of their action the effect of papaverine, chlorpromazine and imipramine produced on a number of blood platelets hemostatic functions was studied. All the three drugs suppress in a characteristic fashion the aggregation on blood platelets caused by thrombin in the Tyrode solution and in a plasma defibrilated by heating, as well as by collogen and ADP in the citrated plasma. Unlike chlorpromazine and imipramine papaverine exerts a strong inhibiting action on the phosphodiesterase activity. Chlorpromazine and imipramine suppress the absorption of serotonin and retraction more intensively than this is done by papaverine and call forth morphological changes in the blood platelets that proceed parallel with changes in the intensity of the photodiffusion and liberation of endogenous serotonin. It is postulated that chlorpromazine and imipramine manifest their inhibitory effect through nonspecific damage of the blood platelets membranes, whereas papaverine does this through exchange of adenine-nucleotides and, especially, of 3',5'-AMP.