Guinea-pig tracheal epithelial cell (EC) shrinkage induced by hyperosmolar challenge.
Jing-Y; Dowdy-JA; Ismailoglu-UB; Van Scott-MR; Fedan-JS
FASEB J 2006 Mar; 20(5)(Part 2):A835
Hyperventilation during exercise is thought to increase the osmolarity of airway surface liquid. Hyperosmolar challenge of EC with mucosal Dmannitol (D-M) in methacholine (MCh)-contracted guinea-pig isolated, perfused trachea elicits smooth muscle relaxation mediated by epithelium-derived relaxing factor (EpDRF). To understand the relationship between EpDRF release and hyperosmolarity-induced changes in cell volume (CV), we examined CV changes in response to challenge of EC with 120 mosM D-M. EC were isolated from tracheas by protease digestion (2%; 1 h) and suspended in Krebs-Henseleit solution. Suspended EC remained viable for more than 5 h as indicated by active beating of cilia and exclusion of trypan blue (90 to 95%). CV was measured using a cell sizer. D-M induced a rapid decrease in CV ( approximately 9% shrinkage) during the first minute. The peak CV decrease occurred between 3 to 5 min (approximately 22% shrinkage). No increase in CV was observed during the next 5 h. The results indicate that hyperosmolar conditions which cause EpDRF-mediated relaxation also evoke EC shrinkage. The rapid onset of the relaxation and CV responses could suggest that signaling pathways are shared.
Laboratory-animals; Animals; Animal-studies; Cell-cultures; Cell-biology; Surface-properties; Exposure-levels; Exposure-assessment
The FASEB Journal