Platelet-activating factor (PAF-acether): present status.
PAF-acether, first discovered in 1971-72, is now recognized as a 1-O-alkyl-2-acetyl-sn-glyceryl-3-phosphorylcholine released from various cells and organs, including macrophages, neutrophils, platelets, the kidney and heart. In this review, we will concentrate on the newest aspects of PAF-acether biochemistry and pathophysiology: (1) PAF-acether is probably formed by murine macrophages through a two-step process implicating successively a phospholipase A2-like enzyme and an acetyltransferase; (2) study of phospholipids structurally related to PAF-acether indicates that the ether linkage at position 1, the short acyl chain at position 2 and the natural optical configuration are critical for biological activity; (3) besides platelet aggregation, PAF-acether induces a platelet-dependent, aspirin-independent bronchoconstriction in the guinea-pig and the monkey. It exhibits also a potent antihypertensive action in the rat, and triggers platelet-independent hemodynamic changes in perfused guinea-pig heart. Thus, this class of phospholipids is gaining increasing importance in pathophysiology.
D000818:Animals; D001779:Blood Coagulation Factors / Q000502:physiology*; D006636:Histamine Release / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D008244:Lysophosphatidylcholines / Q000096:biosynthesis / Q000494:pharmacology / Q000502:physiology*; D008968:Molecular Conformation; D010972:Platelet Activating Factor
D001779:Blood Coagulation Factors; D008244:Lysophosphatidylcholines; D010972:Platelet Activating Factor