The effect of phosphoramidon and epithelium removal on toluene diisocyanate-induced contractions in guinea-pig bronchi.


Journal Article

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 microM) potentiated the contractile response to TDI (0.3 mM) (mean +/- SEM, 23.7 +/- 2.5% versus 67.9 +/- 10.3%, p less than 0.01). Phosphoramidon also increased TDI-induced contractions in tissues without epithelium (36.9 +/- 4.9% versus 52.5 +/- 7.1%, p less than 0.05). Removal of the epithelium increased the contractile response to TDI (23.7 +/- 2.5% versus 36.9 +/- 4.9%, p less than 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.

Full Text

Cited Authors

  • Mapp, CE; Boniotti, A; Papi, A; Chitano, P; Saetta, M; Di Stefano, A; Ciaccia, A; Fabbri, LM

Published Date

  • March 1992

Published In

Volume / Issue

  • 5 / 3

Start / End Page

  • 331 - 333

PubMed ID

  • 1315295

Pubmed Central ID

  • 1315295

Electronic International Standard Serial Number (EISSN)

  • 1399-3003

International Standard Serial Number (ISSN)

  • 0903-1936


  • eng