These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Sodium-hydrogen exchange system in LLC-PK1 epithelium.
    Author: Moran A.
    Journal: Am J Physiol; 1987 Jan; 252(1 Pt 1):C63-7. PubMed ID: 3028147.
    Abstract:
    Sodium influx into LLC-PK1 cells has been characterized. The main amiloride-sensitive pathway for sodium entry through the apical membrane in this cell line is sodium-hydrogen exchange with an apparent Km for sodium of 19 mM. Influx is pH dependent and is amiloride sensitive with K1/2 of 30 microM. Inhibition of the sodium transport by protons (at 1 mM external sodium) is consistent with an interaction of H+ ions at a single site having an apparent pKH of 7.2. These data are similar to those reported previously for brush border membrane (BBM) isolated from kidney proximal tubule. However, in contrast to previously published reports, H+ does not compete with amiloride in blocking Na+ influx and exhibits a mixed inhibition with sodium ions. The latter, together with a direct and independent assessment of amiloride and sodium interaction, indicates that amiloride does not compete with sodium for the same site. Possible explanations for the discrepancy in the literature concerning the interaction of Na+, H+, and amiloride with the Na+-H+ exchanger and the characteristics of the Na+-H+ exchange system in LLC-PK1 are discussed.
    [Abstract] [Full Text] [Related] [New Search]