Changes in the expression of NO synthase isoforms after ozone: the effects of allergen exposure

Jang An-Soo, Choi Inseon-S, Lee Jong-Un, Park Sung-Woo, Lee June-Hyuk, Park, Park Choon-Sik

Description

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 (P enh ) 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 P enh 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. Conclusion 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.

Sujets

• Nitric oxide synthase
• Ozone
• Asthma

Informations

• Publié par: biomed
• Publié le: 01 janvier 2004
• Nombre de lectures: 525
• Langue: English

Extrait

Respiratory Research

BioMedCentral

Open Access Research Changes in the expression of NO synthase isoforms after ozone: the effects of allergen exposure 1 2 3 1 AnSoo Jang* , InseonS Choi , JongUn Lee , SungWoo Park , June 1 1 Hyuk Lee and ChoonSik Park

1 Address: Department of Internal Medicine, Soonchunhyang University Hospital, Bucheon, 1174, Jungdong, Wonmigu, Bucheonsi, Gyeonggi 2 do, 420767 Republic of Korea, Research Institute of Medical Sciences, Department of Internal Medicine, Chonnam National University, 8, Hak 3 1dong, Gwangju, 501757, Republic of Korea and Physiology, Chonnam National University Medical School, Chonnam National University, 5, Hak1dong, Gwangju, 501757, Republic of Korea Email: AnSoo Jang*  [e-mail]; InseonS Choi  [e-mail]; JongUn Lee  [e-mail]; Sung Woo Park  [e-mail]; JuneHyuk Lee  [e-mail]; ChoonSik Park  [e-mail] * Corresponding author

Published: 05 June 2004 Received: 22 May 2003 Accepted: 05 June 2004 Respiratory Research2004,5:5 This article is available from: http://respiratory-research.com/content/5/1/5 © 2004 Jang et al; licensee BioMed Central Ltd. This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original URL.

Nitric oxide synthaseOzoneAsthma

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 (P ) was measured as a marker of airway enh 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 P was increased in the OVA-sensitized/ozone-exposed/OVA-challenged enh 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.

Conclusion: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.

Introduction Asthma is an inflammatory disease of the airways that is

characterized by airway obstruction and increased airway responsiveness [1]. NO (nitric oxide) is a shortlived

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