HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 291/6/G1031    most recent 00483.2005v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Li, J. Articles by Park, K. Search for Related Content PubMed PubMed Citation Articles by Li, J. Articles by Park, K.

LIVER AND BILIARY TRACT

Expression of the Na⁺-HCO₃^– cotransporter and its role in pH_i regulation in guinea pig salivary glands

¹Department of Physiology, College of Dentistry, Seoul National University and Dental Research Institute, Seoul; and ²Department of Biochemistry and Cell Biology, School of Medicine, Kyungpook National University, Taegu, Korea

Submitted 11 October 2005 ; accepted in final form 29 May 2006

Patterns of salivary HCO₃^– secretion vary and depend on species and gland types. However, the identities of the transporters involved in HCO₃^– transport and the underlying mechanism of intracellular pH (pH_i) regulation in salivary glands still remain unclear. In this study, we examined the expression of the Na⁺-HCO₃^– cotransporter (NBC) and its role in pH_i regulation in guinea pig salivary glands, which can serve as an experimental model to study HCO₃^– transport in human salivary glands. RT-PCR, immunohistochemistry, and pH_i measurements from BCECF-AM-loaded cells were performed. The amiloride-sensitive Na⁺/H⁺ exchanger (NHE) played a putative role in pH_i regulation in salivary acinar cells and also appeared to be involved in regulation in salivary ducts. In addition to NHE, NBC also played a role in pH_i regulation in both acini and ducts. In the parotid gland, NBC1 was functionally expressed in the basolateral membrane (BLM) of acinar cells and the luminal membrane (LM) of ducts. In the submandibular gland, NBC1 was expressed only in the BLM of ducts. NBC1 expressed in these two types of salivary glands takes up HCO₃^– and is involved in pH_i regulation. Although NBC3 immunoreactivity was also detected in submandibular gland acinar cells and in the ducts of both glands, it is unlikely that NBC3 plays any role in pH_i regulation. We conclude that NBC1 is functionally expressed and plays a role in pH_i regulation in guinea pig salivary glands but that its localization and role are different depending on the type of salivary glands.

intracellular pH; Na⁺/H⁺ exchange

This article has been cited by other articles:

				D. Heitzmann and R. Warth Physiology and Pathophysiology of Potassium Channels in Gastrointestinal Epithelia Physiol Rev, July 1, 2008; 88(3): 1119 - 1182. [Abstract] [Full Text] [PDF]

				A. Brandes, O. Oehlke, A. Schumann, S. Heidrich, F. Thevenod, and E. Roussa Adaptive redistribution of NBCe1-A and NBCe1-B in rat kidney proximal tubule and striated ducts of salivary glands during acid-base disturbances Am J Physiol Regulatory Integrative Comp Physiol, December 1, 2007; 293(6): R2400 - R2411. [Abstract] [Full Text] [PDF]