Current address: Department of Pharmacology, The University of Utrecht, The Netherlands
Contraction to big endothelin-1, big endothelin-2 and big endothelin-3, and endothelin-converting enzyme inhibition in human isolated bronchi
Article first published online: 30 JAN 2009
2000 British Pharmacological Society
British Journal of Pharmacology
Volume 129, Issue 1, pages 170–176, January 2000
How to Cite
Yap, E. Y. S., Battistini, B. and McKay, K. O. (2000), Contraction to big endothelin-1, big endothelin-2 and big endothelin-3, and endothelin-converting enzyme inhibition in human isolated bronchi. British Journal of Pharmacology, 129: 170–176. doi: 10.1038/sj.bjp.0703006
- Issue published online: 30 JAN 2009
- Article first published online: 30 JAN 2009
- (Received July 7, 1999, Revised October 4, 1999, Accepted October 13, 1999)
- Big endothelin;
- human isolated airways;
- endothelin-converting enzyme;
- CGS 26393;
- CGS 26303;
All three endothelin precursor peptides, i.e. big endothelin-1 (big ET-1), big endothelin-2 (big ET-2) and big endothelin-3 (big ET-3), produced contractile responses in human isolated bronchi, demonstrating the presence of functional endothelin-converting enzyme (ECE) in this tissue.
The maximal contractile responses were equal to 108.4±8.0% (0.1 μM big ET-1; n=4), 85.2±11.8% (0.1 μM big ET-2; n=7) and 43.0±7.2% (0.1 μM big ET-3; n=5) of the reference response to acetylcholine (1 mM).
The response to big ET-1 (0.1 μM), but not endothelin-1 (ET-1, 0.1 μM), was diminished after overnight storage of the tissue at 4°C, demonstrating instability of the enzyme.
The responses to all three big-endothelins were significantly inhibited, by the ECE inhibitors CGS 26393 and CGS 26303, in a concentration-related manner.
The responses to the mature peptides ET-1, endothelin-2 (ET-2), and endothelin-3 (ET-3) were unaffected by CGS 26393 and CGS 26303.
Phosphoramidon (10 μM) also produced an inhibition of the response to big ET-1 that was equivalent to that produced by CGS 26393 (10 μM). Combination of CGS 26393 (10 μM) and phosphoramidon (10 μM) did not produce an additive inhibition.
These results demonstrate the presence of functional ECE for all three big endothelins in human bronchus and inhibition of the enzyme by newly developed orally active ECE inhibitors, as well as phosphoramidon.
British Journal of Pharmacology (2000) 129, 170–176; doi:10.1038/sj.bjp.0703006