Na-K-2Cl cotransport and Cl/HCO₃ exchange are prominent mechanisms for Cl uptake in Cl-secreting epithelial cells. We used immunofluorescence microscopy to delineate the distributions of Na-K-2Cl cotransporter-1 (NKCC1) and anion exchanger-2 (AE2) proteins in rat gastric mucosa (zymogenic zone). Parietal cells (PCs) above the neck of the gastric gland contained abundant AE2 but little or no NKCC1, whereas those in the neck and base contained high NKCC1 but diminished AE2. Lower levels of NKCC1 were detected in surface mucous cells and in cells comprising the blind ends of all glands. Pulse labeling of proliferating cells with bromodeoxyuridine indicated that new PCs originate in the isthmus with scant NKCC1; the subset of PCs that migrate downward expresses NKCC1 abruptly on entering the neck, within 7 days of cell division. Our results suggest that downwardly migrating PCs replace one mechanism for Cl entry (Cl/HCO₃ exchange) with another (Na-K-2Cl cotransport).

gastric mucosa; hydrochloric acid secretion; anion exchanger-2; chloride transport

This article has been cited by other articles:

				P. Kirchhoff, K. Andersson, T. Socrates, S. Sidani, O. Kosiek, and J. P. Geibel Characteristics of the K+-competitive H+,K+-ATPase inhibitor AZD0865 in isolated rat gastric glands Am J Physiol Gastrointest Liver Physiol, November 1, 2006; 291(5): G838 - G843. [Abstract] [Full Text] [PDF]

				I. C. Del Castillo, M. Fedor-Chaiken, J. C. Song, V. Starlinger, J. Yoo, K. S. Matlin, and J. B. Matthews Dynamic regulation of Na+-K+-2Cl- cotransporter surface expression by PKC-{epsilon} in Cl--secretory epithelia Am J Physiol Cell Physiol, November 1, 2005; 289(5): C1332 - C1343. [Abstract] [Full Text] [PDF]

				N. McDaniel, A. J. Pace, S. Spiegel, R. Engelhardt, B. H. Koller, U. Seidler, and C. Lytle Role of Na-K-2Cl cotransporter-1 in gastric secretion of nonacidic fluid and pepsinogen Am J Physiol Gastrointest Liver Physiol, September 1, 2005; 289(3): G550 - G560. [Abstract] [Full Text] [PDF]

				C. S. Chew, C. T. Okamoto, X. Chen, and R. Thomas Drebrin E2 is differentially expressed and phosphorylated in parietal cells in the gastric mucosa Am J Physiol Gastrointest Liver Physiol, August 1, 2005; 289(2): G320 - G331. [Abstract] [Full Text] [PDF]

				P. Kirchhoff, C. A. Wagner, F. Gaetzschmann, K. Radebold, and J. P. Geibel Demonstration of a functional apical sodium hydrogen exchanger in isolated rat gastric glands Am J Physiol Gastrointest Liver Physiol, December 1, 2003; 285(6): G1242 - G1248. [Abstract] [Full Text] [PDF]

				T. Coskun, H. K. Baumgartner, S. Chu, and M. H. Montrose Coordinated regulation of gastric chloride secretion with both acid and alkali secretion Am J Physiol Gastrointest Liver Physiol, November 1, 2002; 283(5): G1147 - G1155. [Abstract] [Full Text] [PDF]

				A. W. Flemmer, I. Gimenez, B. F. X. Dowd, R. B. Darman, and B. Forbush Activation of the Na-K-Cl Cotransporter NKCC1 Detected with a Phospho-specific Antibody J. Biol. Chem., September 27, 2002; 277(40): 37551 - 37558. [Abstract] [Full Text] [PDF]

				S. M. Wall and M. P. Fischer Contribution of the Na+-K+-2Cl- Cotransporter (NKCC1) to Transepithelial Transport of H+, NH4+, K+, and Na+ in Rat Outer Medullary Collecting Duct J. Am. Soc. Nephrol., April 1, 2002; 13(4): 827 - 835. [Abstract] [Full Text] [PDF]

				T. Sonnentag, W.-K. Siegel, O. Bachmann, H. Rossmann, A. Mack, H.-J. Wagner, M. Gregor, and U. Seidler Agonist-induced cytoplasmic volume changes in cultured rabbit parietal cells Am J Physiol Gastrointest Liver Physiol, July 1, 2000; 279(1): G40 - G48. [Abstract] [Full Text] [PDF]

				G. E. Shull, M. L. Miller, and P. J. Schultheis Lessons from Genetically Engineered Animal Models. VIII. Absorption and secretion of ions in the gastrointestinal tract Am J Physiol Gastrointest Liver Physiol, February 1, 2000; 278(2): G185 - G190. [Abstract] [Full Text] [PDF]