Evidence for a chloride conductance in secretory membrane of parietal cells
A fluorescence-quench method using acridine orange as the probe was employed to monitor acid formation in situ by detergent-permeabilized gastric glands. In KCl medium, the addition of ATP to the permeabilized glands resulted in a rapid decrease in fluorescence and addition of valinomycin resulted i...
Saved in:
Published in | The American journal of physiology Vol. 256; no. 2 Pt 1; p. G299 |
---|---|
Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
United States
01.02.1989
|
Subjects | |
Online Access | Get more information |
Cover
Loading…
Summary: | A fluorescence-quench method using acridine orange as the probe was employed to monitor acid formation in situ by detergent-permeabilized gastric glands. In KCl medium, the addition of ATP to the permeabilized glands resulted in a rapid decrease in fluorescence and addition of valinomycin resulted in a second phase of fluorescence quench. The fluorescence was restored by addition of the H+-K+-ATPase inhibitor, Sch 28080. An ATP-dependent fluorescence quench was observed also in K2SO4 or K+-isethionate medium; however, valinomycin was ineffective in the Cl-free media. The ATP-dependent quench could be reversed or prevented by the electrogenic protonophore, tetrachlorosalicylanilide (TCS), in KCl medium but not in Cl-free media. The results with TCS are interpreted as demonstrating a large Cl- conductance in the secretory membrane, whereas the results with valinomycin indicate that resting membranes lack a K+ conductance. The data suggest that a complex KCl pathway that may demonstrate a Cl- conductance is used to activate acid secretion. |
---|---|
ISSN: | 0002-9513 |
DOI: | 10.1152/ajpgi.1989.256.2.G299 |