The actions of Paf-acether (platelet-activating factor) on guinea-pig isolated heart preparations.
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. The non-acetylated Paf-acether analogue, 2-lyso Paf-acether, the enantiomer, and a closely related phospholipid 1, alpha-lysophosphatidylcholine palmitoyl, did not affect coronary flow and contractile force, indicating the specificity of Paf-acether. 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.
D000818:Animals; D003326:Coronary Circulation; D006168:Guinea Pigs; D006321:Heart / Q000502:physiology*; D006339:Heart Rate; D008297:Male; D009200:Myocardial Contraction; D010972:Platelet Activating Factor / Q000502:physiology*
D010972:Platelet Activating Factor