Alterations to potassium fluxes in the heart during chronic dietary potassium depletion.
Dietary K+ depletion in rabbits causes a loss of cellular K+ from skeletal muscle but not from cardiac muscle, and it has been suggested that this is due to a specific protective mechanism in the heart. Net uptake and efflux of 42K was investigated in the interventricular septum of the rabbit. Acute reductions in extracellular [K+] caused a loss of K+ from tissue of both normal and K+ depleted animals. In the K+ depleted group the relationship between [K+]e and net uptake was altered, so that the maximum rate of uptake was increased, and this was obtained at a lower [K+]e. There were no significant changes in K+ efflux. These results would be consistent with an adaptive change to the cardiac cell Na+ pump during chronic K+ depletion.
D000818:Animals; D001692:Biological Transport; D006321:Heart / Q000503:physiopathology*; D008297:Male; D009206:Myocardium / Q000378:metabolism; D011188:Potassium / Q000502:physiology*; D011191:Potassium Deficiency / Q000503:physiopathology*; D011817:Rabbits
D011188:Potassium