|
|
|
|
|
|
|
||
The Journal of General Physiology, Vol 89, 581-598, Copyright © 1987 by The Rockefeller University Press
ARTICLES |
RJ Alpern and M Chambers
To examine whether Cl-coupled HCO3 transport mechanisms were present on the basolateral membrane of the mammalian proximal tubule, cell pH was measured in the microperfused rat proximal convoluted tubule using the pH-sensitive, intracellularly trapped fluorescent dye (2',7')- bis(carboxyethyl)-(5,6)-carboxyfluorescein. Increasing the peritubular Cl concentration from 0 to 128.6 meq/liter caused cell pH to decrease from 7.34 +/- 0.04 to 7.21 +/- 0.04 (p less than 0.001). With more acid extracellular fluid (pH 6.62), a similar increase in the peritubular Cl concentration caused cell pH to decrease by a similar amount from 6.97 +/- 0.04 to 6.84 +/- 0.05 (p less than 0.001). This effect was blocked by 1 mM SITS. To examine the Na dependence of Cl/HCO3 exchange, the above studies were repeated in the absence of luminal and peritubular Na. In alkaline Na-free solutions, peritubular Cl addition caused cell pH to decrease from 7.57 +/- 0.06 to 7.53 +/- 0.06 (p less than 0.025); in acid Na-free solutions, peritubular Cl addition caused cell pH to decrease from 7.21 +/- 0.04 to 7.19 +/- 0.04 (p less than 0.05). The effect of Cl on cell pH was smaller in the absence of luminal and peritubular Na than in its presence. To examine whether the previously described Na/(HCO3)n greater than 1 cotransporter was coupled to or dependent on Cl, the effect of lowering the peritubular Na concentration from 147 to 25 meq/liter was examined in the absence of ambient Cl. Cell pH decreased from 7.28 +/- 0.03 to 7.08 +/- 0.03, a response similar to that observed previously in the presence of Cl. The results demonstrate that Cl/HCO3 (or Cl/OH) exchange is present on the basolateral membrane. Most of Cl/HCO3 exchange is dependent on the presence of Na and may be coupled to it. The previously described Na/(HCO3)n greater than 1 cotransporter is the major basolateral membrane pathway for the coupling of Na and HCO3 and is not coupled to Cl.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  M. D. Parker, P. Bouyer, C. M. Daly, and W. F. Boron Cloning and characterization of novel human SLC4A8 gene products encoding Na+-driven Cl-/HCO3- exchanger variants NDCBE-A, -C, and -D Physiol Genomics, August 1, 2008; 34(3): 265 - 276. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. W. Beyenbach Kidneys sans glomeruli Am J Physiol Renal Physiol, May 1, 2004; 286(5): F811 - F827. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. M. Sciortino, L. D. Shrode, B. R. Fletcher, P. J. Harte, and M. F. Romero Localization of endogenous and recombinant Na+-driven anion exchanger protein NDAE1 from Drosophila melanogaster Am J Physiol Cell Physiol, August 1, 2001; 281(2): C449 - C463. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Tsuruoka, E. R. Swenson, S. Petrovic, A. Fujimura, and G. J. Schwartz Role of basolateral carbonic anhydrase in proximal tubular fluid and bicarbonate absorption Am J Physiol Renal Physiol, January 1, 2001; 280(1): F146 - F154. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Amlal, K. Habo, and M. Soleimani Potassium deprivation upregulates expression of renal basolateral Na+-HCO3- cotransporter (NBC-1) Am J Physiol Renal Physiol, September 1, 2000; 279(3): F532 - F543. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. H. Dantzler, O. K. Serrano, D. E. Abbott, Y. K. Kim, and O. H. Brokl Basolateral regulation of pHi in isolated snake renal proximal tubules in presence and absence of bicarbonate Am J Physiol Regulatory Integrative Comp Physiol, June 1, 1999; 276(6): R1673 - R1681. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. Abuladze, I. Lee, D. Newman, J. Hwang, K. Boorer, A. Pushkin, and I. Kurtz Molecular Cloning, Chromosomal Localization, Tissue Distribution, and Functional Expression of the Human Pancreatic Sodium Bicarbonate Cotransporter J. Biol. Chem., July 10, 1998; 273(28): 17689 - 17695. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
O. H. Brokl, C. L. Martinez, A. Shuprisha, D. E. Abbott, and W. H. Dantzler Regulation of intracellular pH in proximal tubules of avian long-looped mammalian-type nephrons Am J Physiol Regulatory Integrative Comp Physiol, June 1, 1998; 274(6): R1526 - R1535. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Abuladze, I. Lee, D. Newman, J. Hwang, A. Pushkin, and I. Kurtz Axial heterogeneity of sodium-bicarbonate cotransporter expression in the rabbit proximal tubule Am J Physiol Renal Physiol, March 1, 1998; 274(3): F628 - F633. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. L. Martinez, O. H. Brokl, A. Shuprisha, D. E. Abbott, and W. H. Dantzler Regulation of intracellular pH in proximal tubules of avian loopless reptilian-type nephrons Am J Physiol Regulatory Integrative Comp Physiol, December 1, 1997; 273(6): R1845 - R1854. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Z. Wang, P. J. Schultheis, and G. E. Shull Three N-terminal Variants of the AE2 Cl[IMAGE]/HCO(3)[IMAGE] Exchanger Are Encoded by mRNAs Transcribed from Alternative Promoters J. Biol. Chem., March 29, 1996; 271(13): 7835 - 7843. [Abstract] [Full Text] [PDF]
|
|
|
|
