The effect of EGTA and Ca++ in regulation of the brain Na/K-ATP-ase by noradrenaline

Background  

The Na/K-ATPase activity of the brain synaptic plasma membranes (SPM) is regulated by noradrenaline (NA) and the synaptosomal factor SF (soluble protein obtained from the synaptosome cytosol). In the absence of SF, NA inhibits Na/K-ATPase, while, on addition of SF to the reaction medium, there is a NA-dependent activation of Na/K-ATPase . On the other hand, EGTA augments the Na/K-ATPase activity and attenuates the ability of NA to inhibit Na/K-ATPase.