Hydrocortisone and 'macrocortin' inhibit the zymosan-induced release of lyso-PAF from rat peritoneal leucocytes.
Hydrocortisone and the glucocorticoid-induced anti-phospholipase protein macrocortin, were tested as inhibitors of PAF generation. The steroid produced a dose-dependent inhibition of the release of the PAF precursor 2-lyso-PAF, and this effect was mimicked by affinity-purified macrocortin. Neither agent had any effect on the acetylation of lyso-PAF to PAF. Of other drugs tested only phospholipase inhibitors blocked lyso-PAF release and sulphydryl reagents blocked the acetylation step. It is concluded that glucocorticoids inhibit the generation of PAF and this could be an important component of their anti-anaphylactic and anti-inflammatory action.
D000107:Acetylation; D000818:Animals; D001202:Ascitic Fluid; D006023:Glycoproteins / Q000302:isolation & purification / Q000494:pharmacology*; D006854:Hydrocortisone / Q000494:pharmacology*; D047908:Intracellular Signaling Peptides and Proteins; D007962:Leukocytes / Q000187:drug effects / Q000378:metabolism*; D010740:Phospholipases / Q000037:antagonists & inhibitors; D010972:Platelet Activating Factor / Q000031:analogs & derivatives* / Q000096:biosynthesis / Q000378:metabolism; D051381:Rats; D013439:Sulfhydryl Reagents / Q000494:pharmacology; D015054:Zymosan / Q000494:pharmacology
D006023:Glycoproteins; D047908:Intracellular Signaling Peptides and Proteins; C029271:O-deacetyl platelet activating factor; D010972:Platelet Activating Factor; D013439:Sulfhydryl Reagents; C027564:macrocortin protein, rat; D015054:Zymosan; D010740:Phospholipases; D006854:Hydrocortisone