Bioeletric response of guinea-pig tracheal epithelium hypotonic solution.
Knudsen-GA; Van Scott-MR; Leonette-JW; Fedan-JS
FASEB J 2002 Apr; 16(5):A57
Hypotonic solution causes cell swelling. Hypotonic solution in the lumen of the GP trachea depolarizes the E and contracts the airway smooth muscle. This study examined the effects of mucosal hypotonic solution on the bioelectric properties of GP tracheal E mounted in Ussing chambers. Stepwise dilution of the mucosal modified Krebs-Henseleit (MKH) solution (1 % to 50% with water) progressively decreased transepithelial short circuit current (I,,) and increased resistance (R,). Responses to hypo tonicity were unaffected by 1 11M MK-571, 5 11M piriprost, or 10 U/ml apyrase added bilaterally, indicating that L TD4 and ATP were not involved. Mucosal amiloride (30 1iM) decreased basal Isc (10%) but did not affect responses to hypotonicity. Mucosal NPPB (100 11M) decreased basal Isc (88%). Hypotonicity in the presence of NPPB reversed the polarity of Isc and inhibited the increase in R,. but the (delta) Isc was unaffected. Isc also was decreased after reducing [NaCl] in the mucosal bath (113-85 nM). These results indicate that basal across GP tracheal E is mainly due to Cl secretion. The (delta) Isc induced by hypotonicity is consistent with passive transepithelial flux of Na (S-M).
Cell-function; Cell-damage; Bioelectric-effects; Laboratory-animals
Abstract; Conference/Symposia Proceedings
The FASEB Journal, Experimental Biology 2002, New Orleans, Louisiana, April 20-24, 2002