Effects of calcitonin gene-related peptide on airway epithelial functions in dogs.

We studied the effects of calcitonin gene-related peptide (CGRP) on ciliary beat frequency (CBF) and electrical properties of canine tracheal epithelium by a photoelectric method and Ussing's short-circuit technique, respectively. CGRP dose dependently increased CBF, an effect that was accompanied by elevation of intracellular cyclic AMP but not affected by blockade of either Ca2+-influx or arachidonic acid metabolism. In contrast, CGRP elicited only a small and transient increase in short-circuit current without significant alterations in transepithelial potential difference or tissue conductance. These results suggest that CGRP may play a role in regulating airway mucociliary transport function.