Endothelin immunoreactivity of airway epithelium in asthmatic patients.

There is extensive pharmacological and physiological evidence that endothelin-1 influences airway calibre. In mammals, endothelin receptor occur on airway smooth muscle, local storage and release of the peptide have been demonstrated, and inhalation of endothelin-1 induces bronchoconstriction. To investigate the relation between endothelins and asthma the expression of this peptide in endobronchial biopsy specimens was examined immunohistochemically with an antiserum against endothelin-1. Biopsy specimens from 17 asthmatic patients and 11 atopic and non-atopic healthy controls revealed striking differences, with endothelin expression being evident in airways epithelium and vascular endothelium in 11 of the 17 asthmatic patients but in only 1 of 11 controls. These results suggest that endothelins may play a part in the exaggerated bronchomotor tone of asthma.