EFFECT OF SULPHINPYRAZONE ON THE AGGREGATION AND RELEASE REACTIONS OF HUMAN PLATELETS

Sulphinpyrazone at low concentrations inhibits the in vitro aggregation of normal platelets induced by epinephrine, collagen and ristocetin. At higher concentrations sulphinpyrazone also inhibits the thrombin-induced release of platelet factor 4, β-thromboglobulin, serotonin and B-N acetyl glucosaminidase from an unstirred suspension of gel-filtered platelets. The inhibition of release or aggregation could be overcome by increasing the concentration of aggregating agent. Sulphinpyrazone had no effect on the active or passive influx of K+ into the platelet. These inhibitory effects were observed at concentrations of sulphinpyrazone likely to be reached by the daily administration of 800 mg. © 1979.