Bioelectric effects of hyperosmolar solutions on epithelium of guinea-pig isolated trachea.
Fedan-JS; Rengasamy-A; Johnston-RA; Van Scott-MR
FASEB J 2000 Jun; 14(8):A1499
Exposure of guinea-pig trachea (GPT) to mucosal or serosal hypertonic solution elicits relaxation of the airway smooth muscle which is thought to be due to release of epithelium-derived relaxing factor (EpDRF). The purpose of the present study was to further characterize the effects of hypertonic challenge on GPT epithelial bioelectric properties. Tracheas were isolated, cleaned of smooth muscle, opened longitudinally, mounted in Ussing chambers and bathed in modified Krebs-Henseleit (MKH) solution. Transepithelial short circuit current (Isc) was monitored, and resistance (Rt) was calculated periodically by clamping the potential difference to + 10 mV for 0.5 sec. Sucrose, mannitol and urea were added to MKH solution to raise the osmolarity by 8 - 266 mosM. In the apical bath, hypertonic MKH induced a concentration-dependent decrease in Isc and increase in Rt. Basolateral addition of the osmolytes resulted in qualitatively similar changes in Isc and Rt, although all responses were generally smaller than responses to apical hypertonicity. These findings indicate that changes in GPT epithelial bioelectric properties in response to hypertonic challenge parallel smooth muscle relaxation responses in intact GPT, buttressing the hypothesized link between epithelial and smooth muscle function in the airways.
Bioelectric-effects; Laboratory-animals; Animals; Animal-studies; Airway-obstruction; Muscles; Muscle-function; Airway-resistance; Exposure-levels; Respiratory-system-disorders; Pulmonary-system-disorders
Abstract; Conference/Symposia Proceedings
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