The concentration of the Na,K-pump in skeletal and heart muscle in congestive heart failure.
Na,K-ATPase (or the Na,K-pump) is essential for excitability and contractility of muscle tissue. Previous studies have shown a decrease in the concentration of this pump in endomyocardial biopsies from patients with dilated cardiomyopathy. The effect of congestive heart failure on the concentration of Na,K-ATPase in skeletal muscle was assessed in 16 patients by measurement of binding of 3H-ouabain to biopsies of the vastus lateralis muscle. Ten patients had impaired left ventricular function with an ejection fraction of 0.32 +/- 0.03 and a concentration of the Na,K-pump of 229 +/- 15 pmol/g wet weight in the skeletal muscle, whereas 6 patients had an ejection fraction of 0.66 +/- 0.05 (P less than 0.001) and a concentration of 307 +/- 17 pmol/g wet weight (P less than 0.01). In endomyocardial biopsies, the concentration of Na,K-ATPase was 340 +/- 37 and 500 +/- 39 pmol/g wet weight (P less than 0.025) in patients with impaired and normal ventricular function, respectively. There was a significant correlation between the concentration of the Na,K-pump in the biopsies of the skeletal muscle and ejection fraction, as well as between its concentration in the endomyocardial and skeletal muscular biopsies (r = 0.56, P less than 0.025 and r = 0.72, P less than 0.005, respectively). The decrease in concentration of the pump in skeletal muscle may contribute to the limitation of exercise capacity in congestive heart failure.
Nørgaard
A
A
University Department of Cardiology, Aarhus Municipal Hospital, Copenhagen, Denmark.
Bjerregaard
P
P
Baandrup
U
U
Kjeldsen
K
K
Reske-Nielsen
E
E
Thomsen
P E
PE
D000328:Adult; D005260:Female; D006333:Heart Failure / Q000378:metabolism*; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
D000254:Sodium-Potassium-Exchanging ATPase