|
|
|
|
|
|
|
||
The Journal of General Physiology, Vol 101, 715-732, Copyright © 1993 by The Rockefeller University Press
ARTICLES |
PK Gasbjerg, J Funder and J Brahm
Department of Medical Physiology, Panum Institute, University of Copenhagen, Denmark.
Irreversible inhibition, 99.8% of control values for chloride transport in human red blood cells, was obtained by well-established methods of maximum covalent binding of 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS). The kinetics of the residual chloride transport (0.2%, 106 pmol.cm-2 x s-1) at 38 degrees C, pH 7.2) was studied by means of 36Cl- efflux. The outside apparent affinity, expressed by Ko1/2,c, was 34 mM, as determined by substituting external KCl by sucrose. The residual flux was reversibly inhibited by a reexposure to DIDS, and by 4,4'- dinitrostilbene-2,2'-disulfonate (DNDS), phloretin, salicylate, and alpha-bromo-4-hydroxy-3,5-dinitroacetophenone (Killer III) (Borders, C. L., Jr., D. M. Perez, M. W. Lafferty, A. J. Kondow, J. Brahm, M. B. Fenderson, G. L. Breisford, and V. B. Pett. 1989. Bioorganic Chemistry. 17:96-107), to approximately 0.001% of control cells, which is a flux as low as in lipid bilayers. The reversible DIDS inhibition of the residual chloride flux depended on the extracellular chloride concentration, but was not purely competitive. The half-inhibition concentrations at [Cl(o)] = 150 mM in control cells (Ki,o) and covalently DIDS-treated cells (Ki,c) were: DIDS, Ki,c = 73 nM; DNDS, Ki,o = 6.3 microM, Ki,c = 22 microM; phloretin, Ki,o = 19 microM, Ki,c = 17 microM; salicylate, Ki,o = 4 mM, Ki,c = 8 mM; Killer III, Ki,o = 10 microM, Ki,c = 10 microM.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  V. L. Lew and R. M. Bookchin Ion Transport Pathology in the Mechanism of Sickle Cell Dehydration Physiol Rev, January 1, 2005; 85(1): 179 - 200. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. L. Jennings and M. F. Adame Direct estimate of 1:1 stoichiometry of K+-Cl{-} cotransport in rabbit erythrocytes Am J Physiol Cell Physiol, September 1, 2001; 281(3): C825 - C832. [Abstract] [Full Text] [PDF]
|
|
|
|
