A circulating Na+-K+ATPase inhibitor, erythrocyte sodium transport and hypertension in patients with chronic renal failure

Abstract

The level of circulating Na+-K+ATPase inhibitor (% inhibition), erythrocyte ouabain-sensitive 22Na+ efflux rate constant (Kos) and erythrocyte sodium content (RBC Na) were measured in 11 undialysed patients with chronic renal failure, 16 patients on chronic hemodialysis and 16 age-matched normotensive healthy controls. In uremics, % inhibition was significantly higher than that in the controls (p less than 0.001). There were significant correlations between % inhibition and both mean blood pressure (r = 0.74, p less than 0.001) and Kos (r = -0.47, p less than 0.005) for all the groups combined. Hypertensive uremics showed significantly higher % inhibition, lower Kos and higher RBC Na compared with normotensive ones. These data suggest that the elevated level of circulating Na+-K+ ATPase inhibitor may, at least in part, account for the pathogenesis of hypertension in patients with chronic renal failure.