Veterinary Archives, Vol. 76 No. 6, 2006.
Original scientific paper
Low nanomolar concentrations of ouabain may induce higher activity of the Na+/K+-ATPase in human erythrocytes.
Roberto Antolović
; Biology Department, PLIVA Research Institute Ltd., Zagreb, Croatia
Abstract
The inhibitor g-Strophantin, also known as ouabain, is a specific inhibitor of the Na+/K+-ATPase. In this work ouabain has been used for the inhibition of the Na+/K+-ATPase in human erythrocytes and isolated enzyme from pig kidney. Enzymatic activity of the Na+/K+-ATPase has been measured in a broad concentration range of ouabain in two different in vitro investigations. As a potent inhibitor of the sodium pump the cardiotonic steroid ouabain inhibits its enzymatic activity on both isolated human red blood cells and on the purified enzyme from pig kidney. Na+/K+-ATPase activity in erythrocyte can be determined by measuring the ouabain-sensitive uptake of 86Rb (as a congener for potassium). This work provides evidence that very low concentrations of ouabain in the nM range can stimulate increase of Na+/K+-ATPase activity in human erythrocytes, in contrast to inhibition of the purified enzyme from pig kidney, where such an effect was not observed.
Keywords
Na+/K+-ATPase; ouabain; erythrocyte; signal transduction; cardiotonic steroid
Hrčak ID:
22254
URI
Publication date:
20.12.2006.
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