Author: Mandell DL//Devor DC//Madia JV//Lo CY////
Affiliation: Department of Pediatric Otolaryngology, Children's Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, PA 15213, USA
Conference/Journal: Am J Physiol Cell Physiol
Date published: 2003
Other:
Volume ID: 285 , Issue ID: 3 , Pages: C618-22 , Word Count: 122
The purpose of the present study was to compare the effect of 24 h of exposure to 7% O2 (normal middle ear physiological conditions) vs. 21% O2 (found in the middle ear after ventilation tube placement) on transepithelial Na+ absorption and Cl- secretion in cultured gerbil middle ear epithelial cell monolayers. Although no difference in apical Na+ absorption was identified, the UTP-induced stimulation of apical Cl- secretion in the presence of apical Na+ channel blockade with amiloride was significantly enhanced after exposure to 21% O2 compared with 7% O2 exposure. In the presence of a calcium-activated Cl- channel inhibitor, DIDS, UTP-induced stimulation of Cl- secretion after 21% O2 exposure was decreased, suggesting a role for calcium-activated Cl- channels in middle ear Cl- secretion in response to relative hyperoxia