JPET Introducing ALZET?ew Model 2006 Pump

Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by AKERA, T.
Right arrow Articles by BRODY, T. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by AKERA, T.
Right arrow Articles by BRODY, T. M.
Journal of Pharmacology And Experimental Therapeutics, Vol. 170, Issue 1, 17-26, 1969
Copyright © 1969 by American Society for Pharmacology and Experimental Therapeutics

THE EFFECT OF OUABAIN ON SODIUM-AND POTASSIUMACTIVATED ADENOSINE TRIPHOSPHATASE FROM THE HEARTS OF SEVERAL MAMMALIAN SPECIES

TAI AKERA 1, FRAN S. LARSEN 1, and THEODORE M. BRODY 1

1 Department of Pharmacology, Michigan State University, East Lansing, Michigan

The in vitro sensitivity of cardiac (Na+ + K+)-activated adenosine triphosphatase (ATPase) activity [Mg++-dependent, (Na+ + K+)-activated adenosine triphosphate (ATP) phosphohydrolase, Enzyme commssion no. 3.6.1.3] to ouabain was compared with the in vivo sensitivity in the dog, sheep, guinea pig and rat. A (Na+ + K+)-activated ATPase preparation with relatively low Mg++-dependent ATPase activity was obtained with deoxycholate and LiBr treatment of the cardiac microsomal fraction. This method of enzyme preparation was suitable for all species studied. The ouabain sensitivity of the enzyme from various species, as determined by estimation of inhibitor constants (1), was, in decreasing order, dog > pig > sheep > guinea pig >> rat. The K, for potassium was similar in each of the enzyme preparations studied. A kinetic study indicated the competitive nature of the interaction between potassium and ouabain on the enzyme complex at low KCI concentrations and the noncompetitive nature at high KCI concentrations. Doses (micromoles per kilogram) of ouabain required to produce changes in the blood pressure and in the electrocardiogram (ECG) were compared with the concentrations (in micromoles per liter) of ouabain capable of inhibiting enzyme activity in vitro. It is concluded that there is a good agreement between in vitro and in vivo sensitivity to ouabain in the four mammalian species studied. In a separate study, the (Na+ + K+)-activated ATPase activity of preparations obtained from the ventricles of ouabain-infused dogs was significantly lower than those of control animals. ECG changes were utilized as an estimation of the concentration of ouabain. A correlation was observed between the inhibition of enzyme activity and P-Q prolongation on the ECG. That cardiac (Na+ + K+)-ATPase activity is reduced in the intact animal after ouabain administration has hitherto not been demonstrated.

Submitted on March 28, 1969
Accepted on August 4, 1969




This article has been cited by other articles:


Home page
 ScienceHome page
J. Somberg and T. Smith
Localization of the neurally mediated arrhythmogenic properties of digitalis
Science, April 20, 1979; 204(4390): 321 - 323.
[Abstract] [PDF]

Home page
 ScienceHome page
T Akera
Membrane adenosinetriphosphatase: a digitalis receptor?
Science, November 11, 1977; 198(4317): 569 - 574.
[Abstract] [PDF]


Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
All ASPET Journals Molecular Pharmacology Pharmacological Reviews
Molecular Interventions Drug Metabolism and Disposition

Copyright © 1969 by the American Society for Pharmacology and Experimental Therapeutics.