[Calcium metabolism in arterial hypertension. II. Changes in thrombocyte sensitivity to verapamil].

Verapamil produced dose-dependent inhibition of ADP- and TAF-induced increase in thrombocyte calcium concentration in hypertensive patients. Sensitivity to verapamil tested by EC50-half-maximal inhibition of responses to hormones can be weakened in vitro by adrenalin and strengthened by papaverin. Thrombocytes of hypertensive patients were individually sensitive to combination of papaverin and verapamil. The cellular sensitivity to verapamil disappeared when clonidine was substituted for verapamil and was restored when papaverin was added to verapamil.