Endothelium‐derived relaxing factor inhibits in vitro platelet aggregation

Abstract

1 We studied the effects of endothelium-derived relaxing factor (EDRF), bovine retractor penis muscle inhibitory factor and sodium nitroprusside, three stimulants of guanylate cyclase, on the in vitro aggregation of washed human platelets. 2 Platelet aggregation induced either by collagen or by the thromboxane A₂ analogue U46619 was inhibited by all three agents. 3 The anti-aggregatory effect of each agent was inhibited by haemoglobin. 4 The anti-aggregatory effect of EDRF was potentiated by superoxide dismutase. 5 These findings are discussed in relation to a potential role for EDRF in haemostasis.