Stimulation of brain Na+, K+-ATPase by norepinephrine in vivo: prevention by receptor antagonists and enhancement by repeated stimulation.

The role of alpha 1- and beta-noradrenergic receptors in the stimulation of the K+-p-nitrophenylphosphatase activity and ouabain binding associated with rat brain Na+, K+-ATPase by acute or repeated yohimbine were examined. Repeated yohimbine increased enzyme activity and ouabain binding by about 25%; this was prevented by the alpha 1-receptor antagonist prazosin and decreased by the beta-antagonist propranolol. Pretreatment with repeated yohimbine increased the stimulation of enzyme activity by acute yohimbine while the stimulation was prevented by prazosin pretreatment.