Inhaled ammonium persulphate inhibits non-adrenergic, non-cholinergic relaxations in the guinea pig isolated trachea.
Respiration
; 79(5): 411-9, 2010.
Article
de En
| MEDLINE
| ID: mdl-19923787
ABSTRACT
BACKGROUND:
Persulphates can act both as irritants and sensitizers in inducing occupational asthma. A dysfunction of nervous control regulating the airway tone has been hypothesized as a mechanism underlying bronchoconstriction in asthma.OBJECTIVES:
It was the aim of this study to investigate whether inhaled ammonium persulphate affects the non-adrenergic, non-cholinergic (NANC) inhibitory innervation, the cholinergic nerve-mediated contraction or the muscular response to the spasmogens, carbachol or histamine, in the guinea pig epithelium-free, isolated trachea.METHODS:
Male guinea pigs inhaled aerosols containing ammonium persulphate (10 mg/m(3) for 30 min for 5 days during 3 weeks). Control animals inhaled saline aerosol. NANC relaxations to electrical field stimulation at 3 Hz were evaluated in whole tracheal segments as intraluminal pressure changes. Drugs inactivating peptide transmission, nitric oxide synthase, carbon monoxide production by haem oxygenase-2 and soluble guanylyl cyclase were used to assess the involvement of various inhibitory neurotransmitters. Carbachol and histamine cumulative concentration-response curves were obtained.RESULTS:
In both groups, nitric oxide and carbon monoxide participated to the same extent as inhibitory neurotransmitters. In exposed animals, the tracheal NANC relaxations were reduced to 45.9 +/- 12.1% (p < 0.01). The cholinergic nerve-mediated contractions to electrical field stimulation and the muscular response to histamine were not modified by ammonium persulphate exposure. The muscular response to carbachol was unaffected up to 1 microM. Conversely, the response to the maximal concentration of carbachol (3 microM) was increased (p < 0.01).CONCLUSION:
Ammonium persulphate inhalation at high concentrations impairs the nervous NANC inhibitory control in the guinea pig airways. This may represent a novel mechanism contributing to persulphate-induced asthma.
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Trachée
/
Sulfate d'ammonium
/
Relâchement musculaire
Limites:
Animals
Langue:
En
Journal:
Respiration
Année:
2010
Type de document:
Article