Comparison of bioelectric responses of fresh tracheal epithelium (FE) and air-liquid interface epithelial cell cultures (CE) from guinea pigs.
Wu-DXY; Van Scott-MR; Fedan-JS
Am J Respir Crit Care Med 2003 Apr; 167(7):A394
To determine whether primary air-interface cultured guinea-pig tracheal epithelial cells (CE) retain the bioelectric response profile of fresh epithelial cells (FE), we compared short circuit current (Isc) and transepithelial resistance (Rt) responses to ion transport blockers, methacholine (MCh) , and hyperosmolar challenge, using Ussing chambers. In FE, baseline values were: Isc: 49+/-4 uA/cm2, Rt: 97+/-6 omega cm2; in CE, Isc: 9.3+/-0.4 uA/cm2, Rt: 787+/-98 omega-cm2 (FE vs. CE, p<0.05). Amiloride (30 uM), bumetanide (10 uM) and ouabain (10 uM) reduced Isc in FE and CE, and there were no differences (% change in Isc) in the effects seen in FE and CE. Iberiotoxin (0.1 uM) had no effect on Isc in FE or CE. NPPB (10 um) decreased Isc by 11 % in FE and 71 % in CE (p<0.05). Serosal MCh (0.3 um) elicited a monotonic increase in Isc. In FE, MCh caused a transient increase in Isc, which was followed by a plateau; the former response was inhibited by NPPB. The enhanced effect of NPPB on CE and responses to MCh suggests that a relative shift in Cl- secretion had occurred in CE. In the presence of MCh, the addition of Dmannitol (D-M; 0.27-266.8 mosM) to elevate osmolarity elicited concentration-dependent, progressive decreases in Isc in FE. In CE, D-M increased Isc over the range of 0.27-84.3 mosM, but decreased Isc and Rt over the range of 84.3-266.8 mosM. The results suggest that CE causes marked changes in the bioelectric response to NPPB, MCh and hyperosmolarity, some of which are attributable to changes in Cl- secretion. These changes might reflect a phenotypic modification occurring in CE or the absence of modulators originating in the airway wall.
Bioelectric-effects; Cell-cultures; Airway-obstruction; Airway-resistance; Animal-studies; Animals; Laboratory-animals; In-vitro-study
Abstract; Conference/Symposia Proceedings
Disease and Injury: Asthma and Chronic Obstructive Pulmonary Disease
American Journal of Respiratory and Critical Care Medicine, 2003 International Conference, The American Thoracic Society, Seattle, WA, May 16-21, 2003