Airway hyper-responsiveness to neurokinin A and bradykinin following Mycoplasma pneumoniae infection associated with reduced epithelial neutral endopeptidase
| Autor: | Atsushi Chiyotani, Jun Tamaoki, Etsuko Tagaya, Atsushi Nagai, Minako Araake |
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| Rok vydání: | 1998 |
| Předmět: |
Male
Agonist medicine.medical_specialty medicine.drug_class Neurokinin A Bradykinin Hamster In Vitro Techniques Biology Microbiology Epithelium chemistry.chemical_compound Cricetinae Isometric Contraction Internal medicine Pneumonia Mycoplasma medicine Animals Protease Inhibitors Neprilysin Mesocricetus Phosphoramidon Glycopeptides Muscle Smooth respiratory system Antibodies Bacterial Mycoplasma pneumoniae Trachea Endocrinology medicine.anatomical_structure chemistry Respiratory epithelium Bronchial Hyperreactivity Respiratory tract |
| Zdroj: | Microbiology. 144:2481-2486 |
| ISSN: | 1465-2080 1350-0872 |
| DOI: | 10.1099/00221287-144-9-2481 |
| Popis: | To determine whether mycoplasma infection produces airway hyper-responsiveness to tachykinins and bradykinin and, if so, to elucidate the role of neutral endopeptidase (NEP), isolated hamster tracheal segments were studied under isometric conditionsin vitro.Nasal inoculation withMycoplasma pneumoniaepotentiated contractile responses to neurokinin A and bradykinin, causing a leftward shift of the dose-response curves to a lower concentration by 1 log unit for each agonist, whereas there was no response with acetylcholine. Pretreatment of tissues with the NEP inhibitor phosphoramidon augmented neurokinin A- and bradykinin-induced contractions in saline-treated control tissues, but did not further potentiate the responsiveness inM. pneumoniae-infected tissues. NEP activity in the tracheal epithelium, but not in epithelium-denuded tissues, was decreased in infected animals. These results suggest thatM. pneumoniaeinfection causes airway bronchoconstrictor hyper-responsiveness to neurokinin A and bradykinin and that this effect may be associated with an inhibition of epithelial NEP activity. |
| Databáze: | OpenAIRE |
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