TY - JOUR
T1 - Repeated allergen exposure enhances excitatory nonadrenergic noncholinergic nerve-mediated bronchoconstriction in sensitized guinea-pigs
AU - Kageyama, N.
AU - Ichinose, M.
AU - Igarashi, A.
AU - Miura, M.
AU - Yamauchi, H.
AU - Sasaki, Y.
AU - Ishikawa, J.
AU - Tomaki, M.
AU - Shirato, K.
N1 - Copyright:
Copyright 2007 Elsevier B.V., All rights reserved.
PY - 1996
Y1 - 1996
N2 - The effect of repeated allergen inhalation challenge on the airway excitatory nonadrenergic noncholinergic (e-NANC) nerve-mediated bronchoconstrictor response was studied in ovalbumin (OA) sensitized guinea-pigs. Three weeks after sensitization, OA inhalation, 0.03% for 3 min (challenged group), or saline inhalation (control group) was repeated every day for 4 weeks. The e-NANC nerve function was examined in vitro by means of isometric tension measurement of main bronchi. After pretreatment with atropine (10-6 M) and propranolol (10-6 M), we performed electrical field stimulation (EFS) or exogenous neurokinin A (NKA) administration. In the challenged group, EFS-induced main bronchial contraction was significantly greater than that of the control group (p < 0.05 or p < 0.01), but exogenous NKA-mediated responses were almost the same in both groups. The e-NANC-induced main bronchial contractions after EFS were enhanced by pretreatment with the neutral endopeptidase inhibitor, phosphoramidon, to the same degree in the control and challenged groups, indicating that the peptide degradation mechanisms were not impaired even in the challenged group. Substance P immunoreactivities in the lung of the challenged group were significantly higher than those of the control group. These results suggest that chronic airway inflammation after repeated allergen challenge increases excitatory nonadrenergic noncholinergic nerve function, possibly by enhancing sensory neuropeptide production and/or release.
AB - The effect of repeated allergen inhalation challenge on the airway excitatory nonadrenergic noncholinergic (e-NANC) nerve-mediated bronchoconstrictor response was studied in ovalbumin (OA) sensitized guinea-pigs. Three weeks after sensitization, OA inhalation, 0.03% for 3 min (challenged group), or saline inhalation (control group) was repeated every day for 4 weeks. The e-NANC nerve function was examined in vitro by means of isometric tension measurement of main bronchi. After pretreatment with atropine (10-6 M) and propranolol (10-6 M), we performed electrical field stimulation (EFS) or exogenous neurokinin A (NKA) administration. In the challenged group, EFS-induced main bronchial contraction was significantly greater than that of the control group (p < 0.05 or p < 0.01), but exogenous NKA-mediated responses were almost the same in both groups. The e-NANC-induced main bronchial contractions after EFS were enhanced by pretreatment with the neutral endopeptidase inhibitor, phosphoramidon, to the same degree in the control and challenged groups, indicating that the peptide degradation mechanisms were not impaired even in the challenged group. Substance P immunoreactivities in the lung of the challenged group were significantly higher than those of the control group. These results suggest that chronic airway inflammation after repeated allergen challenge increases excitatory nonadrenergic noncholinergic nerve function, possibly by enhancing sensory neuropeptide production and/or release.
KW - airway inflammation
KW - antigen
KW - asthma
KW - neutral endopeptidase
KW - substance P
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U2 - 10.1183/09031936.96.09071439
DO - 10.1183/09031936.96.09071439
M3 - Article
C2 - 8836656
AN - SCOPUS:0030018031
VL - 9
SP - 1439
EP - 1444
JO - European Respiratory Journal
JF - European Respiratory Journal
SN - 0903-1936
IS - 7
ER -