To evaluate the role of airway neutral endopeptidase 24.11 (NEP) and epithelium removal in the contraction of airway smooth muscle in response to toluene diisocyanate (TDI), we studied the effects of the NEP inhibitor, phosphoramidon, on TDI-induced contractions of guinea-pig bronchial rings with intact epithelium and without epithelium. In preparations with intact epithelium, phosphoramidon (10 μM) potentiated the contractile response to TDI (0.3 mM) mean±SEM, 23.7 ± 2.5% versus 67.9 ± 10.3%, p <0.01). Phosphoramidon also increased TDI-induced contractions in tissues without epithelium (36.9 ± 4.9% versus 52.5 ±7.1%, p <0.05). Removal of the epithelium increased the contractile response to TDI (23.7 ± 2.5% versus 36.9 ± 4.9%, p <0.05). These results demonstrate the response to TDI is increased in epithelium-free compared to intact bronchi and that NEP 24.11 modulates the effects of endogenously released tachykinins by TDI at all of the sites where NEP is found in the airways.
|Number of pages||3|
|Journal||European Respiratory Journal|
|Publication status||Published - 1992|
- Neutral endopeptidase
- Toluene diisocyanate
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine