Ouabain-like activity in human cerebrospinal fluid.

Abstract

Human cerebrospinal fluid has been found to mimic the effect of ouabain on net Na+ efflux and 86Rb+ influx across erythrocyte membranes and on the in vitro activity of a purified Na+/K+-ATPase (ATP phosphohydrolase, EC 3.6.1.3) derived from canine kidney. These results indicate the possible existence in human cerebrospinal fluid of an endogenous factor with ouabain-like activity, which might be linked to sodium metabolism.