Effects of endothelins 1, 2 and 3 on mucosal blood flow in the upper airways.

The three endothlins 1, 2 and 3 (ET-1, ET-2 and ET-3) are 21-amino-acid peptides which in a previous study in the rabbit have been shown to increase both mucociliary activity in the maxillary sinus in vivo and ciliary beat frequency (CBF) in sinus and tracheal samples in vitro. We have also demonstrated positive immunohistochemical staining for endothelin in the epithelium of samples from both maxillary sinus and trachea. the aims of the present investigation were to study the effects of the three endothlins on mucosal blood flow in the maxillary sinus of rabbits and the nasal mucosa of humans. ET-1, ET-2 and ET-3 decreased mucosal blood flow in the maxillary sinus of rabbits measured in vivo with laser Doppler flowmetry (LDF). Significant dose-response relationships were established for all endothelins. A comparison of the regression lines of the dose-response relationships for ET-1 and ET-2 did not show any difference, whereas the regression line of the dose-response relationships for ET-3 differed sign...