Intracellular chloride in submucosal gland cells.
The chloride ion concentration within isolated tracheal submucosal gland cells was studied micro-spectrofluorometrically using a fluorescent dye, 6-methoxy-N-(3-sulfopropyl) quinolinium (SPQ), that is quenched by Cl-. Cells from normal weanling swine and from a cystic fibrosis (CF) patient were used. Ion substitution experiments showed that cell fluorescence increased in both cell types when bath Cl- was replaced with the impermeant anion glucuronate. Following a Donnan-type ion substitution that kept the product of the bath K+ and Cl- concentrations constant, reducing bath chloride had little effect on fluorescence for normal cells, but caused a marked increase for CF cells. Thus, K+ and Cl- ions have approximately the same Nernst potential in control submucosal gland cells; in contrast, cells from a CF patient concentrated Cli, resulting in a Cl- Nernst potential that was more positive than the K+ Nernst potential. This finding is consistent with the hypothesis that CF submucosal gland cells have a decreased Cl- permeability.
Dwyer
T M
TM
Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson 39216-4505.
Farley
J M
JM
D000818:Animals; D003550:Cystic Fibrosis / Q000378:metabolism* / Q000473:pathology; D005088:Exocrine Glands / Q000378:metabolism*; D006801:Humans; D008297:Male; D009092:Mucous Membrane / Q000378:metabolism; D011188:Potassium / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D013552:Swine; D014132:Trachea / Q000378:metabolism* / Q000473:pathology
D011188:Potassium