Effect of topical nasal pharmaceuticals on sodium and chloride transport by human airway epithelia.

Abstract

The human airway epithelium lines the respiratory tract from the nasal mucosa to the bronchioles. Electrolyte transport by these epithelia is crucial in maintaining the appropriate volume and salt composition of the airway surface fluid. When this epithelium becomes functionally impaired, the airways are more prone to respiratory infections. We studied the effect of six common topical agents that are commonly used to treat rhinorrhea and nasal inflammation on the transepithelial resistance, sodium, and chloride transport of primary cultures of human airway epithelia grown at the air-liquid interface. The pharmaceuticals fluticasone propionate, cromolyn sodium, ipratropium bromide, azelastine, oxymetazoline, and normal saline were used and the electrical function of the epithelia was studied in Ussing chambers. Azelastin and ipratropium bromide-treated epithelia were found to have a significant decrease in transepithelial resistance. Both normal saline and fluticasone propionate resulted in significant increases in amiloride-sensitive short circuit currents that reflect sodium transport. Finally, normal saline resulted in a significant increase in bumetanide-sensitive short circuit current that reflects chloride transport across the epithelia. The data presented may explain a mechanism by which some topical pharmaceuticals help reduce rhinorrhea, and may point to some unwanted side effects of some pharmaceuticals on the electrolyte transport of the airway epithelia. In summary, several of the common topical nasal agents alter the electrolyte transport of the nasal airway epithelia. The in vivo significance of these findings is to be determined.