| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Department of Clinical Pharmacology, Jichi Medical School, Kawachi, Tochigi 329-0498, Japan; 2 Medical Service, Veterans Affairs Puget Sound Health Care System, University of Washington, Seattle, Washington 98108; and 3 Department of Pediatrics, University of Rochester School of Medicine, Rochester, New York 14642
Membrane-bound carbonic anhydrase (CA)
is critical to renal acidification. The role of CA activity on the
basolateral membrane of the proximal tubule has not been defined
clearly. To investigate this issue in microperfused rabbit proximal
straight tubules in vitro, we measured fluid and HCO3
absorption and cell pH before and after the extracellular CA inhibitor
p-fluorobenzyl-aminobenzolamide was applied in the bath to
inhibit only basolateral CA. This inhibitor was 1% as permeant as
acetazolamide. Neutral dextran (2 g/dl, molecular mass 70,000) was used
as a colloid to support fluid absorption because albumin could affect
CO2 diffusion and rheogenic HCO3 efflux.
Indeed, dextran in the bath stimulated fluid absorption by 55% over
albumin. Basolateral CA inhibition reduced fluid absorption (~30%) and markedly decreased HCO3 absorption
(~60%), both reversible when CA was added to the bathing solution.
In the presence of luminal CA inhibition, which reduced fluid (~16%)
and HCO3 (~66%) absorption, inhibition of
basolateral CA further decreased the absorption of fluid (to 74% of
baseline) and HCO3 (to 22% of baseline). CA
inhibition also alkalinized cell pH by ~0.2 units, suggesting the
presence of an alkaline disequilibrium pH in the interspace, which
would secondarily block HCO3 exit from the cell and
thereby decrease luminal proton secretion (HCO3
absorption). These data clearly indicate that basolateral CA has an
important role in mediating fluid and especially HCO3
absorption in the proximal straight tubule.
in vitro microperfusion; acidification; cell pH; inulin; dextran; para-fluorobenzyl-aminobenzolamide; hydratase assay
This article has been cited by other articles:
|
|
 |
|
  H. J. Bell and P. Haouzi Acetazolamide suppresses the prevalence of augmented breaths during exposure to hypoxia Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2009; 297(2): R370 - R381. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Breton and D. Brown New insights into the regulation of V-ATPase-dependent proton secretion Am J Physiol Renal Physiol, January 1, 2007; 292(1): F1 - F10. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Tsuruoka, S. Watanabe, J. M. Purkerson, A. Fujimura, and G. J. Schwartz Endothelin and nitric oxide mediate adaptation of the cortical collecting duct to metabolic acidosis Am J Physiol Renal Physiol, October 1, 2006; 291(4): F866 - F873. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. Pastor-Soler, C. Pietrement, and S. Breton Role of Acid/Base Transporters in the Male Reproductive Tract and Potential Consequences of Their Malfunction Physiology, December 1, 2005; 20(6): 417 - 428. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. M. Purkerson and G. J. Schwartz Expression of membrane-associated carbonic anhydrase isoforms IV, IX, XII, and XIV in the rabbit: induction of CA IV and IX during maturation Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2005; 288(5): R1256 - R1263. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Watanabe, S. Tsuruoka, S. Vijayakumar, G. Fischer, Y. Zhang, A. Fujimura, Q. Al-Awqati, and G. J. Schwartz Cyclosporin A produces distal renal tubular acidosis by blocking peptidyl prolyl cis-trans isomerase activity of cyclophilin Am J Physiol Renal Physiol, January 1, 2005; 288(1): F40 - F47. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Petrovic, S. Barone, A. M. Weinstein, and M. Soleimani Activation of the apical Na+/H+ exchanger NHE3 by formate: a basis of enhanced fluid and electrolyte reabsorption by formate in the kidney Am J Physiol Renal Physiol, August 1, 2004; 287(2): F336 - F346. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. P. J. Diecke, Q. Wen, J. M. Sanchez, K. Kuang, and J. Fischbarg Immunocytochemical localization of Na+-HCO3- cotransporters and carbonic anhydrase dependence of fluid transport in corneal endothelial cells Am J Physiol Cell Physiol, June 1, 2004; 286(6): C1434 - C1442. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. M. Pelis, J. E. Goldmeyer, J. Crivello, and J. L. Renfro Cortisol alters carbonic anhydrase-mediated renal sulfate secretion Am J Physiol Regulatory Integrative Comp Physiol, December 1, 2003; 285(6): R1430 - R1438. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Petrovic, L. Ma, Z. Wang, and M. Soleimani Identification of an apical Cl-/HCO-3 exchanger in rat kidney proximal tubule Am J Physiol Cell Physiol, September 1, 2003; 285(3): C608 - C617. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Tsuruoka, G. J. Schwartz, M. Wakaumi, K. Nishiki, H. Yamamoto, J. M. Purkerson, and A. Fujimura Nitric Oxide Production Modulates Cyclosporin A-Induced Distal Renal Tubular Acidosis in the Rat J. Pharmacol. Exp. Ther., June 1, 2003; 305(3): 840 - 845. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. J. Schwartz, A. M. Kittelberger, R. H. Watkins, and M. A. O'Reilly Carbonic anhydrase XII mRNA encodes a hydratase that is differentially expressed along the rabbit nephron Am J Physiol Renal Physiol, February 1, 2003; 284(2): F399 - F410. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Petrovic, Z. Wang, L. Ma, and M. Soleimani Regulation of the apical Cl--/HCO-3 exchanger pendrin in rat cortical collecting duct in metabolic acidosis Am J Physiol Renal Physiol, January 1, 2003; 284(1): F103 - F112. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K.-P. Yip, S. Tsuruoka, G. J. Schwartz, and I. Kurtz Apical H+/base transporters mediating bicarbonate absorption and pHi regulation in the OMCD Am J Physiol Renal Physiol, November 1, 2002; 283(5): F1098 - F1104. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. Karhumaa, K. Kaunisto, S. Parkkila, A. Waheed, S. Pastorekova, J. Pastorek, W. S. Sly, and H. Rajaniemi Expression of the transmembrane carbonic anhydrases, CA IX and CA XII, in the human male excurrent ducts Mol. Hum. Reprod., July 1, 2001; 7(7): 611 - 616. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Petrovic, Z. Spicer, T. Greeley, G. E Shull, and M. Soleimani Novel Schering and ouabain-insensitive potassium-dependent proton secretion in the mouse cortical collecting duct Am J Physiol Renal Physiol, January 1, 2002; 282(1): F133 - F143. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
