Document Detail

The Na+/K+ATPase mediates the alpha 1-adrenoceptor stimulated increase in 86Rb(+)-uptake in isolated ventricular cardiomyocytes from adult rat heart.
MedLine Citation:
PMID:  9178370     Owner:  NLM     Status:  MEDLINE    
The aim of the present study was to identify the mechanism(s) responsible for the alpha 1-adrenoceptor stimulated increase in potassium uptake in ventricular cardiomyocytes isolated from adult rat heart. The Na+/K+ATPase blocker ouabain the Na+/K+/2Cl(-)-cotransporter blocker bumetanide, the Na+/H(+)-exchanger blocker HOE 694 and the potassium channel blocker 4-aminopyridine were used as experimental tools. 86Rb+ was used as potassium analogue. The basal 86Rb(+)-uptake rate was 0.25 +/- 0.01 ml/g protein x min. Maximal alpha 1-adrenoceptor stimulation increased the 86Rb(+)-uptake 38 +/- 2%. Ouabain dose dependently eliminated the alpha 1-adrenoceptor stimulated response with a -logIC50-value of 3.64 +/- 0.23. Bumetanide did not affect the stimulated response, and there was no effect of bumetanide on the ouabain sensitive component. HOE 694 and 4-aminopyridine had no effect on the stimulated 86Rb(+)-uptake. Ouabain and HOE 694 also dose dependently inhibited a portion of the basal 86Rb(+)-uptake (about 60% and 20%, respectively), but there was no effect of bumetanide or 4-aminopyridine on the basal 86Rb(+)-uptake. The results show that the Na+/K+ATPase alone mediates the alpah 1-adrenoceptor stimulated increase in potassium uptake in this preparation of ventricular cardiomyocytes isolated from adult rat heart.
H Viko; J B Osnes; T Skomedal
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Research communications in molecular pathology and pharmacology     Volume:  96     ISSN:  1078-0297     ISO Abbreviation:  Res. Commun. Mol. Pathol. Pharmacol.     Publication Date:  1997 Apr 
Date Detail:
Created Date:  1997-08-05     Completed Date:  1997-08-05     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  9437512     Medline TA:  Res Commun Mol Pathol Pharmacol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  89-106     Citation Subset:  IM    
Department of Pharmacology, University of Oslo, Norway.
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MeSH Terms
4-Aminopyridine / pharmacology
Bumetanide / pharmacology
Cardiac Glycosides / pharmacology
Cells, Cultured
Dose-Response Relationship, Drug
Drug Combinations
Guanidines / pharmacology
Heart Ventricles / cytology,  metabolism
Myocardium / cytology,  metabolism*
Ouabain / pharmacology
Potassium / metabolism*
Potassium Channel Blockers
Rats, Wistar
Receptors, Adrenergic, alpha-1 / drug effects,  physiology*
Rubidium / metabolism*
Rubidium Radioisotopes
Sodium-Hydrogen Antiporter / pharmacology
Sodium-Potassium-Exchanging ATPase / metabolism*,  pharmacology
Sulfones / pharmacology
Reg. No./Substance:
0/Cardiac Glycosides; 0/Drug Combinations; 0/Guanidines; 0/Potassium Channel Blockers; 0/Receptors, Adrenergic, alpha-1; 0/Rubidium Radioisotopes; 0/Sodium-Hydrogen Antiporter; 0/Sulfones; 141923-47-9/3-methylsulfonyl-4-piperidinobenzoyl guanidine; 28395-03-1/Bumetanide; 504-24-5/4-Aminopyridine; 630-60-4/Ouabain; 7440-09-7/Potassium; 7440-17-7/Rubidium; EC ATPase

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