title: Lipid inhibitors of platelet-activating factor (PAF) in normal human plasma.
abstract: Endogenous, human plasma-derived lipids that inhibit the platelet stimulating activity of platelet-activating factor (PAF) have been identified. Chromatographic fractionation of neutral lipid PAF inhibitors revealed a majority of PAF inhibitory activity comigrating with cholesterol and a second peak localized with free fatty acids. Plasma phospholipids demonstrated three distinct PAF inhibitory fractions in TLC regions corresponding to those of sphingomyelin, phosphatidylcholine and phosphatidylethanolamine. Three fractions (one neutral lipid and two phospholipid) specifically inhibited PAF-induced platelet activation. Thus, there are both specific and non-specific lipid inhibitors of PAF in normal human plasma. These plasma lipids may be important in the specific regulation of the diverse, potent biological activities of PAF in various physiological states.
authors.affiliation: Department of Pathology, University of Texas Health Science Center, San Antonio 78284-7750, USA.
authors.forename: D S
authors.initials: DS
authors.lastname: Woodard
authors.forename: K K
authors.initials: KK
authors.lastname: Ostrom
authors.forename: L M
authors.initials: LM
authors.lastname: McManus
mesh_terms: D000096:Acetone; D000328:Adult; D011232:Chemical Precipitation; D002784:Cholesterol / Q000097:blood; D002855:Chromatography, Thin Layer; D005227:Fatty Acids / Q000097:blood; D005260:Female; D006801:Humans; D007700:Kinetics; D008055:Lipids / Q000097:blood* / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D010743:Phospholipids / Q000097:blood; D010972:Platelet Activating Factor / Q000037:antagonists & inhibitors*
chemical_list: D005227:Fatty Acids; D008055:Lipids; D010743:Phospholipids; D010972:Platelet Activating Factor; D000096:Acetone; D002784:Cholesterol