Inhibition by loperamide of chloride transport across canine cultured tracheal epithelium.

We studied the effect of loperamide on electrical properties of canine cultured tracheal epithelium by Ussing's short-circuited technique. Addition of loperamide to the mucosal bath decreased the short-circuit current, transepithelial potential difference and conductance, whereas submucosal loperamide had no effect. This inhibitory effect was attenuated by furosemide, diphenylamine-2-carboxylate and Cl(-)-free medium but not by amiloride or naloxone. Thus, loperamide may selectively inhibit Cl- secretion across airway epithelium through a non-opiate-dependent mechanism.