Ozone-induced nasal hyperresponsiveness to tachykinins in guinea pigs

Ching Yin Ho, Ching Ting Tan, Hung Huey Tsai, Yu Ru Kou

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Objective: To assess role of hydroxyl radials in the ozone-induced upper airway hyper-responsiveness to tachykinins. Methods: A prospective, controlled, animal model (n = 96) was performed. Half of them exposed to air (A-group, placebo) and the other half exposed to 3 ppm ozone (O-group) for 2 h. Two hours post air/ozone exposure, animals were anesthetized and equally randomized to be pretreated with one of the three treatments, including saline vehicle, dimethylthiourea (DMTU; 500 mg/kg m, a hydroxyl radical scavenger), or phosphoramidon (Phos; 2 mg/kg, an inhibitor for neutral endopeptidase). Ten minutes after pretreatment, half of the animals in each group were i.v. injected with capsaicin (2 μg/kg), and the other half were i.v. injected with substance P (10 μg/kg) to produce Evans blue dye extravasation. Results: Nasal exudative response to capsaicin or substance P in O-group was found to be significantly greater than that in A-group. This ozone-induced nasal airway hyperresponsiveness was largely prevented by DMTU. Phosphoramidon produced a similar nasal airway hyperresponsiveness in the A-group, but failed to alter ozone-induced nasal airway hyperresponsiveness in O-group. In sharp contrast, only substance P, but not capsaicin, produced a laryngeal exudative response in the A-group, which was similar to that in the O-group. The laryngeal exudative response to substance P was not significantly affected by DMTU or Phos. Conculsion: In the guinea-pig model, hydroxyl radicals play a vital role in the development of ozone-induced nasal airway hyperresponsiveness to tachykinins. It is possibly mediated through the suppressive action of ozone on the tachykinin degradation.

Original languageEnglish
Pages (from-to)463-467
Number of pages5
JournalAmerican Journal of Rhinology
Volume22
Issue number5
DOIs
Publication statusPublished - Sep 2008

Keywords

  • Neutral endopeptidase
  • Oxygen radicals
  • Ozone
  • Phosphoramidon
  • Substance P
  • Tachykinins
  • Upper airway hyper-reactivity

ASJC Scopus subject areas

  • Otorhinolaryngology

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