Effect of histamine on electrical and ion transport properties of tracheal epithelium

Abstract

Previously we showed that the active transport of Cl-toward and Na+ away from the tracheal lumen creates an electrical potential difference (lumen negative) across the canine tracheal epithelium in vitro. The present study examined the effect of histamine on the electrical properties and ion transport of the canine tracheal epithelium in vitro. In six pairs of membranes, under short-circuit conditions, histamine (10(-4) M) significantly increased the net flux toward the lumen of Cl- from 1.7 +- 0.5 SE to 2.4 +- 0.6 microneq/cm2-h and Na+ from -0.4 +- 0.3 to 0.2 +- 0.3 microneq/cm2-h. The response to histamine was inhibited by diphenhydramine (10(-6) M), an H1-receptor antagonist, but not by burimamide (10(-4) M), an H2-receptor antagonist. These results are consistent with the hypothesis that an H1-type receptor mediates the increase of ion flux toward the lumen due to histamine. Increased ion flux toward the lumen may mediate water secretion into the airway lumen and have important effects on the physical properties of the liquid through which the respiratory cilia beat.