Extracellular Mg(2+)-dependent Na+, K+, and Cl- efflux in squid giant axons. – ScienceOpen
1
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Extracellular Mg(2+)-dependent Na+, K+, and Cl- efflux in squid giant axons.

      Read this article at

      ScienceOpenPublisherPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          An extracellular Na+ (Nao)-dependent Mg2+ efflux process that requires intracellular ATP has been proposed as the sole mechanism responsible for Mg2+ extrusion in internally dialyzed squid axons (12). We have shown that this exchanger can also "reverse" and mediate an extracellular Mg2+ (Mgo)-dependent Na+ efflux (16). We have extended these studies and found that, in the presence of ouabain, bumetanide, tetrodotoxin, and K+ channel blockers and in the absence of extracellular Na+, K+, and bicarbonate, intracellular K+ and Cl- are also involved in the Mgo-dependent Na+ efflux process. Two main observations support this view: 1) operation of the Mgo-dependent Na+ efflux requires the presence of intracellular K+ and Cl-, and 2) Mgo removal produces a reversible and nearly identical reduction in the magnitude of the simultaneous efflux of the ionic pairs K(+)-Na+ and Cl(-)-Na+. These results suggest that the putative bumetanide-insensitive Na-Mg exchanger also transports K+ and Cl-.

          Related collections

          Author and article information

          Journal
          Am J Physiol
          The American journal of physiology
          American Physiological Society
          0002-9513
          0002-9513
          Apr 1994
          : 266
          : 4 Pt 1
          Affiliations
          [1 ] Department of Physiology and Biophysics, Finch University of Health Sciences, Chicago Medical School, Illinois 60064.
          Article
          10.1152/ajpcell.1994.266.4.C1112
          8178958
          41512e42-dd10-4ff0-ab8d-f9fb0b130fd8
          History

          Comments

          Comment on this article