Effect of chronic surgical denervation of dog heart on myocardial Na+-K+ pump.
The effect of chronic denervation of the myocardium on myocardial Na+-K+ pump activity and numbers of pump sites was studied in dogs. Right ventricular biopsies were taken immediately before and 4 wk after chronic surgical denervation, when depletion of norepinephrine is complete. Na+-K+ pump activity was assayed by ouabain-sensitive 86Rb uptake into ventricular tissue slices. The number of pump sites was measured by [3H]ouabain binding in ventricular tissue slices. Ouabain-sensitive Rb uptake was increased after denervation by an average of 147%. [3H]-ouabain binding at a concentration of 1.25 X 10(-6) M increased by an average of 27.6% after denervation. Acutely applied norepinephrine (2 X 10(-7) M) stimulated ouabain-sensitive Rb uptake both before and after denervation. The stimulation was greater after denervation, indicating supersensitivity. The cause of these changes is not known.
D000818:Animals; D004285:Dogs; D005260:Female; D006321:Heart / Q000294:innervation*; D008297:Male; D009121:Muscle Denervation; D009206:Myocardium / Q000201:enzymology*; D010042:Ouabain / Q000378:metabolism; D012413:Rubidium / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D013997:Time Factors
D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase; D012413:Rubidium