Comparison of beta adrenoceptors in bovine airway epithelium and smooth muscle cells.

This study was undertaken to compare the characteristics of beta-adrenoceptors in bovine airway epithelium and smooth muscle cells. [3H]Dihydroalprenolol (DHA) was used as the radioligand. There was a significant difference in both the affinity and the density of the specific [3H]DHA binding in both the membranes. The maximum number of binding sites was about two fold higher and the affinity about six fold greater in the epithelial membranes as compared to those in the smooth muscle membranes. Because the integrity of airway epithelium is very important for pulmonary function and airway epithelium is very rich in beta-adrenoceptors, it is possible that the beneficial effects of beta-adrenoceptor agonists in asthma and other airway diseases could, at least in part, be due to their action on epithelium.