The actions of Paf‐acether (platelet‐activating factor) on guinea‐pig isolated heart preparations

Abstract

1 Paf-acether (platelet-activating factor) is a phospholipid capable of stimulating platelets to release their granular contents and cause platelet aggregation. When Paf-acether was administered to isolated heart preparations from normal guinea-pigs there was a significant concentration-dependent reduction in coronary flow and contractile force. The high concentration of Paf-acether was equally effective in reducing these cardiac parameters in the presence of atropine. 2 The non-acetylated Paf-acether analogue, 2-lyso Paf-acether, the enantiomer, and a closely related phospholipid 1,α-lysophosphatidylcholine palmitoyl, did not affect coronary flow and contractile force, indicating the specificity of Paf-acether. 3 These data demonstrate a potent effect of Paf-acether on cardiac function. Whether or not these effects are direct or mediated through generation of endogenous mediators remains to be established.