Stimulation of sodium transport by oxidants in middle ear epithelium in primary culture.

Abstract

Primary cultures of middle ear (ME) epithelial cells from gerbils were used to investigate the effect on ion transport of reactive oxygen species (ROS), which are major inflammatory mediators. Short-circuit current measurements revealed an unexpected result: low concentrations of ROS induced an increase in transepithelial sodium transport. This stimulation was mediated by the endogenous synthesis of prostaglandin E2, which in turn increased the intracellular adenosine 3',5'-cyclic monophosphate (cAMP) content. This effect was blunted by indomethacin. By stimulating sodium and fluid transport, ROS may reduce the depth of the periciliary fluid layer, and may thus be involved in the impairment of mucociliary clearance which initiates chronic otitis media.