Partial characterization of the embryo-derived platelet-activating factor in mice.
The platelet-activating factor (PAF) produced by mouse embryos showed similar kinetics of action and dose-response curve, in a bioassay, as did 1-0-alkyl-2-acetyl-sn-glyceryl-3-phosphocholine (PAF-acether). The activity of the embryo-derived PAF was not affected by inhibitors of the ADP (pyruvate kinase with phosphoenol pyruvate) or cyclo-oxygenase (indomethacin) pathways of platelet activation. Chlorpromazine, an inhibitor of the PAF-acether pathway of platelet activation, caused a significant inhibition of the effects of embryo-derived PAF. Phospholipases A2, C and D significantly inhibited the activity while lipase had no effect, suggesting a phospholipid structure. All the embryo-derived PAF was found in the chloroform fraction after chloroform:methanol (2:1 v/v) extraction, as was PAF-acether. Both factors migrated at a similar rate (Rf 0.10-0.12) on silica thin-layer chromatography (chloroform:methanol:water; 65:35:4 by vol.). The embryo-derived PAF therefore displays chemical, biochemical and physiological properties similar to those of PAF-acether.
D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D002746:Chlorpromazine / Q000494:pharmacology; D004622:Embryo, Mammalian / Q000032:analysis*; D005260:Female; D007213:Indomethacin / Q000494:pharmacology; D007700:Kinetics; D051379:Mice; D010728:Phosphoenolpyruvate / Q000494:pharmacology; D010972:Platelet Activating Factor / Q000032:analysis* / Q000502:physiology
D010972:Platelet Activating Factor; D010728:Phosphoenolpyruvate; D002746:Chlorpromazine; D007213:Indomethacin