(Na +-K +)atpase activity in erythrocyte membranes of spontaneously, one kidney-one wrapped, and deoxycorticosterone acetatenacl hypertensive rats

Abstract

(Na +-K +)ATPase activity in erythrocyte membranes of spontaneously (SHR), one kidney one wrapped, and deoxycorticosterone acetate (DOCA)-NaCl hypertensive rats was studied. (Na +-K +)ATPase activity decreased in both prehypertensive (6 weeks old) and hypertensive (14 weeks old) stages of SHR, suggesting that the alteration of this enzymic activity may be due to a pre-existing defect in the membrane rather than being a consequence of hypertension. By contrast, (Na +-K +)ATPase activity remained unchanged in the one kidney-one wrapped hypertensive rats, whereas that of one kidney-one wrapped normotensive rats as well as that of DOCA-NaCl hypertensive rats was increased significantly (P < 0.05). These changes were specific for (Na +-K +)ATPase, since Mg 2+-ATPase activity was not altered. The susceptibility of (Na +-K +)ATPase to the inhibitory action of ouabain was not changed significantly. These findings indicate that (Na +-K +)ATPase activities of erythrocyte membranes isolated from the different types of hypertensive rats were subject to different changes. Whether this phenomenon applies to the clinical distinctions among the various types of hypertension remains a subject for further investigation.