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This Article Full Text Full Text (PDF) All Versions of this Article: 285/5/C1047    most recent 00581.2002v1 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 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 Web of Science (6) Citing Articles via Google Scholar Google Scholar Articles by Granger, D. Articles by Laprade, R. Search for Related Content PubMed PubMed Citation Articles by Granger, D. Articles by Laprade, R.

MEMBRANE TRANSPORTERS, ION CHANNELS, AND PUMPS

Na⁺/H⁺ exchangers in the human eccrine sweat duct

¹Groupe d'Étude des Protéines Membranaires, Université; de Montréal, Montreal, Quebec, Canada H3C 3J7; and ²Unilever Research Port Sunlight, Bebington, Wirral, United Kingdom CH63 3JW

Submitted 12 December 2002 ; accepted in final form 19 June 2003

Using an anti-NHE1 antibody, we demonstrate the presence of a Na⁺/H⁺ exchanger of isoform 1 (NHE1) in the human eccrine sweat duct. A strong staining was observed at the basolateral membrane of the outer cell layer (NHE1_basal), at the junction between inner and outer cells layers (NHE1_inter), and along the lateral membranes (NHE1_later) of all cells of the duct. At the luminal membrane, no staining was demonstrated either for NHE1 or NHE3. To investigate Na⁺/H⁺ mediated proton transport, straight sweat duct portions were isolated and perfused in vitro under HCO₃^--free conditions. In the presence of basolateral 5-ethyl-N-isopropyl amiloride (EIPA), an acidification of 0.29 ± 0.03 pH units was observed, whereas no effect was observed with luminal EIPA. Bath sodium removal generated a stronger acidification (0.41 ± 0.09 pH units). Removal of luminal sodium (in the absence or presence of basolateral EIPA), or low luminal chloride, led to an alkalinization, presumably due to a decrease in intracellular sodium, strongly suggesting functional activity of NHE1_inter. We therefore conclude that in the sweat duct, NHE1 plays a major role in intracellular pH regulation.

5-ethyl-N-isopropyl amiloride; chloride; intracellular pH measurements; immunolocalization; epithelial cells

This article has been cited by other articles:

				L. N. Nejsum, J. Praetorius, and S. Nielsen NKCC1 and NHE1 are abundantly expressed in the basolateral plasma membrane of secretory coil cells in rat, mouse, and human sweat glands Am J Physiol Cell Physiol, August 1, 2005; 289(2): C333 - C340. [Abstract] [Full Text] [PDF]