[Effect of histamine on electrical properties in canine tracheal epithelium]

To characterize the action of histamine on ion transport across the airway mucosa, we measured the electrical properties of cultured tracheal epithelium from dogs by Ussing's short-circuited technique in vitro. The addition of histamine to the submucosal side increased short-circuit current (Isc), whereas mucosal addition of histamine had no effect. The histamine-induced increase in Isc was dose-dependent with the maximal increase from the baseline value and EC50 being 4.4 +/- 0.5 microA/cm2 and 10(-6) M, respectively. We also tested the effects of pharmacological blocking agents on the histamine-induced Isc increase. The effect of histamine on Isc was partially inhibited by pretreatment of cells with amiloride, furosemide and diphenylamine carboxylate. Furthermore, the effect of histamine was inhibited by pyrilamine, but not by cimetidine. To determine the contributions of several intracellular second messenger systems to the histamine-induced increase in Isc, we studied the change of Isc by pretreatment of cells with indomethacin, mepacrine and H-7. The increase in Isc produced by histamine was inhibited by indomethacin and mepacrine but not H-7. These results suggest that histamine stimulates both Cl secretion and Na absorption and may affect the subsequent movement of water across the airway epithelium through the activation of submucosal H1-receptor probably involving prostaglandin synthesis.