title: Changes in the expression of NO synthase isoforms after ozone: the effects of allergen exposure.
abstract: BACKGROUND
  The functional role of nitric oxide (NO) and various nitric oxide synthase (NOS) isoforms in asthma remains unclear.
  
  
  OBJECTIVE
  This study investigated the effects of ozone and ovalbumin (OVA) exposure on NOS isoforms.
  
  
  METHODS
  The expression of inducible NOS (iNOS), neuronal NOS (nNOS), and endothelial NOS (eNOS) in lung tissue was measured. Enhanced pause (Penh) was measured as a marker of airway obstruction. Nitrate and nitrite in bronchoalveolar lavage (BAL) fluid were measured using a modified Griess reaction.
  
  
  RESULTS
  The nitrate concentration in BAL fluid from the OVA-sensitized/ozone-exposed/OVA-challenged group was greater than that of the OVA-sensitized/saline-challenged group. Methacholine-induced Penh was increased in the OVA-sensitized/ozone-exposed/OVA-challenged group, with a shift in the dose-response curve to the left, compared with the OVA-sensitized/saline-challenged group. The levels of nNOS and eNOS were increased significantly in the OVA-sensitized/ozone-exposed/OVA-challenged group and the iNOS levels were reduced compared with the OVA-sensitized/saline-challenged group.
  
  
  CONCLUSIONS
  In mice, ozone is associated with increases in lung eNOS and nNOS, and decreases in iNOS. None of these enzymes are further affected by allergens, suggesting that the NOS isoforms play different roles in airway inflammation after ozone exposure.
authors.affiliation: Department of Internal Medicine, Soonchunhyang University Hospital, Bucheon, 1174, Jung-dong, Wonmi-gu, Bucheon-si, Gyeonggi-do, 420-767 Republic of Korea. jas877@schbc.ac.kr
authors.forename: An-Soo
authors.initials: AS
authors.lastname: Jang
authors.forename: Inseon-S
authors.initials: IS
authors.lastname: Choi
authors.forename: Jong-Un
authors.initials: JU
authors.lastname: Lee
authors.forename: Sung-Woo
authors.initials: SW
authors.lastname: Park
authors.forename: June-Hyuk
authors.initials: JH
authors.lastname: Lee
authors.forename: Choon-Sik
authors.initials: CS
authors.lastname: Park
mesh_terms: D000485:Allergens / Q000633:toxicity; D000818:Animals; D001249:Asthma / Q000139:chemically induced* / Q000201:enzymology*; D016084:Bronchoconstriction / Q000187:drug effects; D004781:Environmental Exposure / Q000009:adverse effects; D005260:Female; D008168:Lung / Q000187:drug effects* / Q000201:enzymology* / Q000473:pathology / Q000503:physiopathology; D051379:Mice; D008807:Mice, Inbred BALB C; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D010047:Ovalbumin / Q000633:toxicity*; D010126:Ozone / Q000633:toxicity*; D020033:Protein Isoforms / Q000378:metabolism
chemical_list: D000485:Allergens; D020033:Protein Isoforms; D010126:Ozone; D010047:Ovalbumin; D019001:Nitric Oxide Synthase