title: Nitric oxide synthase and nitric oxide production in in vivo-derived mast cells.
abstract: Nitric oxide (NO) is a potent mediator synthesized by a variety of cells involved in inflammatory reactions. We investigated the expression of NO synthase (NOS) in rat peritoneal mast cells (PMC). Small amounts of eNOS mRNA were detected basally, whereas neither mRNA for iNOS nor nNOS was detected in unstimulated PMC. Following stimulation by antigen, interferon-gamma (IFN-gamma), or anti-CD8 antibody, PMC up-regulated iNOS mRNA expression. In situ RT-PCR confirmed that iNOS mRNA originated from PMC. Production of iNOS protein was confirmed in stimulated PMC by immunohistochemistry. Upon stimulation with antigen, IFN-gamma, or anti-CD8, nitrite production was increased significantly (8.4+/-0.6, 7.6+/-0.9, and 6.6+/-0.9 microM/2x10(5) cells/48 h NO2-, respectively; P<0.01), whereas unstimulated PMC released 2.1 +/- 0.3 microM/2 x 10(5) cells/48 h NO2-. These findings demonstrate that in vivo-derived PMC transcribe and translate mRNA for NOS and produce NO.
authors.affiliation: Glaxo-Heritage Asthma Research Laboratory, Pulmonary Research Group, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada. Mark.Gilchrist@ualberta.ca
authors.forename: Mark
authors.initials: M
authors.lastname: Gilchrist
authors.forename: Michelle
authors.initials: M
authors.lastname: Savoie
authors.forename: Osamu
authors.initials: O
authors.lastname: Nohara
authors.forename: Fiona L
authors.initials: FL
authors.lastname: Wills
authors.forename: John L
authors.initials: JL
authors.lastname: Wallace
authors.forename: A D
authors.initials: AD
authors.lastname: Befus
mesh_terms: D000818:Animals; D007371:Interferon-gamma / Q000494:pharmacology; D008297:Male; D008407:Mast Cells / Q000378:metabolism*; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D012333:RNA, Messenger; D009569:Nitric Oxide; D007371:Interferon-gamma; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; C496318:Nos2 protein, rat; C496316:Nos3 protein, rat