The distribution of sodium-potassium-activated adenosine triphosphatase in medulla and cortex of the kidney

Ernesto D. Hendler; Jorge Torretti; Franklin H. Epstein

doi:10.1172/JCI106612

¹Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06510

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¹Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06510

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¹Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06510

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Published in Volume 50, Issue 6 on June 1, 1971
J Clin Invest. 1971;50(6):1329–1337. https://doi.org/10.1172/JCI106612.
© 1971 The American Society for Clinical Investigation

Published June 1, 1971 - Version history

The activity of sodium-potassium-activated adenosine triphosphatase (Na-K-ATPase) is considerably higher in homogenates of outer medulla than in the cortex or papilla of the kidney. The enzyme has similar kinetic characteristics in both cortex and medulla, and binds ouabain in the same proportion. The discrepancy in enzymatic activity is not paralleled by similar change in the activity of adenyl cyclase, 5′nucleotidase, glucose-6-phosphatase, or succinic dehydrogenase. Na-K-ATPase is also higher in distal convoluted tubules (ventral slices) than in the proximal tubules (dorsal slices) of the kidney of Amphiuma. The high concentration of Na-K-ATPase in the red medulla of the kidney is probably related to the presence here of the thick ascending limb of the loop of Henle, and this has important implications with regard to the mechanism of sodium reabsorption by different portions of the nephron.