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

Search MEDLINE/PubMed


  • Title: Modes of operation of an electroneutral Na+/Li+ countertransport in human skin fibroblasts.
    Author: Zerbini G, Mangili R, Gabellini D, Pozza G.
    Journal: Am J Physiol; 1997 Apr; 272(4 Pt 1):C1373-9. PubMed ID: 9142864.
    Abstract:
    An elevated activity of erythrocyte Na+/Li+ countertransport (SLC) is an intermediate phenotype of human essential hypertension, but cells other than erythrocytes have not been studied. Therefore, we have examined several transport modes of Na+/Li+ exchange in human skin fibroblasts. External Na+-stimulated Li+ efflux was 152 +/- 31 (SE) nmol x mg protein(-1) x min(-1) (n = 8). At intracellular pH 7.3, intracellular Na+-stimulated Li+ influx, intracellular Li+-stimulated Na+ influx, and external Li+-stimulated Na+ efflux were very similar, indicating the presence of a tightly coupled 1:1 SLC. This pathway was not affected by 5-(N,N-dimethyl)-amiloride and changes in the membrane potential, but phloretin and intracellular acidification (intracellular pH 6.8) were markedly inhibitory. Kinetic analyses of the external Na+ site also compared with SLC, although the internal site appeared to show a low affinity for Li+. We conclude that an SLC pathway similar to that in human erythrocytes is expressed in human skin fibroblasts.
    [Abstract] [Full Text] [Related] [New Search]