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: Reduction of the equilibrium binding of cardiac glycosides and related compounds to Na+,K+-ATPase as a possible mechanism for the potassium-induced reversal of their toxicity.
    Author: Akera T, Temma K, Wiest SA, Brody TM.
    Journal: Naunyn Schmiedebergs Arch Pharmacol; 1978 Sep; 304(2):157-65. PubMed ID: 212685.
    Abstract:
    The influence of potassium ions on the equilibrium state of the binding of cardiac glycosides and their derivatives to partially purified dog heart and rat brain enzyme preparations was studied in vitro. The addition of potassium to the incubation mixture containing enzyme preparation, 3H-ouabain, Na+, Mg2+ and ATP, at the time when the binding reaction is close to equilibrium, caused an immediate reduction of the bound drug concentration; the concentration apparently shifting toward a lower equilibrium state. The degree of the potassium-induced reduction in bound drug concentration was dependent on the potassium concentration and on the chemical structure of the compound. The binding of aglycones, pentacetyl-gitoxin and cassaine was affected to a greater extent than that of the glycosides. These data suggest that one of the mechanisms by which potassium antagonizes the toxic actions of digitalis on the heart is to reduce the drug binding to cardiac Na+,K+-ATPase.
    [Abstract] [Full Text] [Related] [New Search]