In vitro exposure to nitrogen dioxide (NO2) does not alter bronchial smooth muscle responsiveness in ovalbumin-sensitized guinea-pigs.


Journal Article

The aim of this study was to investigate whether in vitro exposure to NO2 affects responsiveness in ovalbumin-sensitized guinea-pig bronchi. Twenty-three animals were sensitized by three weekly intraperitoneal injections of 1 mg ovalbumin in saline with Freund's adjuvant; twenty-one control guinea-pigs received the diluent alone. From each animal, the two main bronchi were obtained and cannulated, then exposed in vitro to a constant intraluminal flow of: (i) either air or 2.5 ppm NO2 with four spikes of 10 ppm NO2 for 2 h; (ii) either air or 10 ppm NO2 for 4 h. A bronchial ring obtained from each animal before exposure was kept in aerated Krebs-Henseleit solution. Rings from bronchi exposed to air, NO2, or kept in Krebs solution were studied isometrically. We performed overall and non-adrenergic non-cholinergic voltage-response curves to electrical field stimulation, concentration-response curves to acetylcholine and to neurokinin A, followed by administration of 10 mg/ml ovalbumin. We did not find any significant difference in bronchial smooth muscle responsiveness between nonexposed, air-exposed and NO2-exposed bronchi, as well as between bronchi from control and sensitized animals. We conclude that in vitro exposure to NO2 does not alter bronchial smooth muscle responsiveness to either specific or non-specific stimuli.

Full Text

Cited Authors

  • Chitano, P; Coser, E; Lucchini, RE; Papi, A; Saetta, M; Maestrelli, P; Faggian, D; Plebani, M; Ciaccia, A; Fabbri, LM

Published Date

  • August 1994

Published In

Volume / Issue

  • 7 / 4

Start / End Page

  • 251 - 257

PubMed ID

  • 7620240

Pubmed Central ID

  • 7620240

International Standard Serial Number (ISSN)

  • 0952-0600

Digital Object Identifier (DOI)

  • 10.1006/pulp.1994.1028


  • eng