Lack of Correlation Between Natriuretic Activity and Inhibition of Renal Na-K-Activated ATPase.

Publisher Website
Google Scholar
Abstract
Summary Ethacrynic acid, which is a potent natriuretic in man and dog but inactive in the rat, and furosemide, which is a potent natriuretic in man and dog as well as in the rat, were compared for their ability to inhibit microsomal Na-K-activated ATPase following in vivo administration in the rat. Both agents were found to inhibit the activity of this enzyme. Furosemide produced a significant natriuretic response whereas ethacrynic acid did not. Therefore, no correlation between natriuretic activity and enzyme inhibition could be made with these agents. This study does not rule out a correlation between Na-K-activated ATPase and natriuretic activity but it does question the practice of determining Na-K-activated ATPase in vitro and attempting to relate this to responses in vivo.