title: Nasal allergen challenge generates 1-0-hexadecyl-2-lyso-sn-glycero-3-phosphocholine.
abstract: We studied antigen-induced platelet activating factor and the 1-0-hexadecyl-2-lyso-sn-glycero-3-phosphocholine (lyso-PAF) in nasal lavage fluids (NLF) by combined gas chromatography/mass spectrometric analysis (GC/MS). During the early allergic reaction, there was a dramatic increase in the levels of lyso-PAF that peaked at 15 min (2.6 +/- 5.2 ng/ml, mean +/- SEM, n = 6). Increasing doses of antigen produced a dose-dependent increase in the levels of lyso-PAF that peaked at the highest dose. Levels of lyso-PAF correlated strongly with those of N-alpha-tosyl-L-arginine methyl ester (TAME)-esterase activity (rs = 0.82, p = 0.0001) and histamine (rs = 0.57, p = 0.002). There was a no significant increase in the quantity of lyso-PAF found in NLF from allergic individuals challenged with diluent or nonallergic individuals challenged with antigen. In subjects showing a late phase reaction, as indicated by symptoms and histamine release, we detected lyso-PAF along with TAME-esterase activity and histamine during the late phase reaction. In contrast to lyso-PAF, PAF levels were near or below the detection limit of the assay in NLF and remained unchanged after antigen challenge. We also investigated the potential pathways for lyso-PAF generation from 2-acetylated phospholipids. We found that the time required for deacetylation of 50% of [3H]PAF (t1/2) to lyso-PAF was 50 min in baseline secretions and 10 and 22 min in NLF obtained 10 min and 24 h after antigen challenge, respectively. These data suggested that catabolic pathways were present in NLF.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Medicine, (Division of Allergy and Clinical Immunology and Pulmonary and Critical Care Medicine), Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: M H
authors.initials: MH
authors.lastname: Shin
authors.forename: F J
authors.initials: FJ
authors.lastname: Averill
authors.forename: W C
authors.initials: WC
authors.lastname: Hubbard
authors.forename: F H
authors.initials: FH
authors.lastname: Chilton
authors.forename: F M
authors.initials: FM
authors.lastname: Baroody
authors.forename: M C
authors.initials: MC
authors.lastname: Liu
authors.forename: R M
authors.initials: RM
authors.lastname: Naclerio
mesh_terms: D000210:Acute-Phase Reaction / Q000209:etiology; D000293:Adolescent; D000328:Adult; D000418:Albumins / Q000032:analysis; D000704:Analysis of Variance; D004305:Dose-Response Relationship, Drug; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D006632:Histamine / Q000032:analysis; D006801:Humans; D008297:Male; D017817:Nasal Lavage Fluid / Q000737:chemistry*; D009299:Nasal Provocation Tests; D010741:Phospholipases A / Q000032:analysis; D010972:Platelet Activating Factor / Q000031:analogs & derivatives* / Q000032:analysis* / Q000378:metabolism; D006255:Rhinitis, Allergic, Seasonal / Q000150:complications / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology*; D013997:Time Factors; D014106:Tosylarginine Methyl Ester / Q000032:analysis
chemical_list: D000418:Albumins; C029271:O-deacetyl platelet activating factor; D010972:Platelet Activating Factor; D006632:Histamine; D014106:Tosylarginine Methyl Ester; D010741:Phospholipases A