正常血壓白鼠와 單一腎臟 및 腎動脈結紮高血壓白鼠에서의 心筋 Na^+, K^+－ATPase에 關한 硏究 = Myocardial Na^+, K^+-ATPase in Normotensive and One-Kidney, One-Clip Hypertensive Rats

목차 (Table of Contents)

• Myocardial Na+, K+-ATPase activity of one kidney, one-clip hypertensive rats was compared with that of normotensive rats. All animals were healthy as assessed by body weight, serum creatinine and examination of vital organs. The yield of protein per gm cardiac wet weight in the microsomal and sarcolemmal membrane fractions was the same for both normotensive and hypertensive rat hearts. However, the protein yield per heart was greater in the hypertensive relative to the normotensive animals which was consistent with the presence of hypertrophy, as indicated by the increase in the ratio of ventricular weight to body weight.
• Na^+, K^+-ATPase activity, sodium-dependent phosphorylation and ouabain binding were signifi cantly decreased in the hypertensive rat heart when the data were expressed in units per gram tissue wet weight but not when expressed in units per heart. The molecular activity or turnover number of myocardial Na^+, K^+-ATPase was the same in both groups of animals.
• These results suggest that the decrease in specific Na^+, K^+-ATPase activity in the rat heart made hypertensive by removing one kidney and constricting the renal artery of the other kidney is secondary to the cardiac hypertrophy, not by the decrease of the sodium pump sites or their turnover number per heart.