Subcellular elemental composition in isolated cardiac myocytes from rabbit following chronic potassium depletion and acute repletion, studied by X-ray microanalysis.
X-ray microanalysis was used to estimate K, Na, Cl, Mg, P and S within the mitochondria and the myofibrillar regions of cardiac myocytes from rabbits, following dietary potassium depletion. K depletion caused no changes in mitochondrial K, but myofibrillar K was reduced. There were no changes in Na, Mg or Cl. Both areas showed increases in P but decreases in S. Acute K repletion resulted in a significant overshoot of K in both areas, coupled with a profound decrease in Cl. P was reduced in the mitochondria alone. These results may be partly explained by adaptive changes in Na+ pump activity.
Ward
J P
JP
Division of Medicine and Physiology, United Medical School, London.
Warley
A
A
D000818:Animals; D004032:Diet; D004573:Electrolytes / Q000378:metabolism*; D004577:Electron Probe Microanalysis; D008297:Male; D008929:Mitochondria, Heart / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D011191:Potassium Deficiency / Q000378:metabolism*; D011817:Rabbits
D004573:Electrolytes