Stereospecific bioactions of 5‐hydroxyicosatetraenoate

Abstract
5(S)‐Hydroxyicosatetraenoate stimulates human polymorphonuclear neutrophils (PMNs) to raise their cytosolic calcium. It also potentiates the cells' degranulation responses to platelet‐activating factor and diacylglycerols. We synthesized 5(R)‐hydroxyicosatetraenoate and found it to be 20–100‐fold weaker than the natural isomer in these assays. Thus, the arachidonic acid metabolite activates PMNs by a stereospecific possibly receptor‐mediated mechanism.