Regulation of (Na+, K+) adenosinetriphosphatase of nerve ending membranes: action of norepinephrine and a soluble factor.
Norepinephrine added in vitro to nerve ending membranes from rat cerebral cortex stimulates the activity of (Na+, K+) adenosinetriphosphatase (ATPase) only in the presence of the soluble brain fraction. In its absence norepinephrine inhibits the enzyme. (Mg2+)ATPase also showed stimulation by norepinephrine in the presence of the soluble fraction, but of lesser magnitude. The activation of (Na+, K+)ATPase by norepinephrine is not reproduced by cyclic AMP and is not antagonized by either alpha- or beta-adrenergic blocking agents. These results suggest that the stimulation caused by norepinephrine is a direct effect on the enzyme and is not mediated by cyclic AMP or adrenergic receptors.
D000251:Adenosine Triphosphatases / Q000378:metabolism; D001921:Brain / Q000201:enzymology*; D002540:Cerebral Cortex / Q000201:enzymology; D003600:Cytosol / Q000201:enzymology; D004789:Enzyme Activation / Q000187:drug effects; D008274:Magnesium / Q000494:pharmacology; D009411:Nerve Endings / Q000201:enzymology*; D009441:Neurilemma / Q000201:enzymology; D009638:Norepinephrine / Q000494:pharmacology*; D010643:Phenoxybenzamine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
D010643:Phenoxybenzamine; D011433:Propranolol; D000251:Adenosine Triphosphatases; D000254:Sodium-Potassium-Exchanging ATPase; D008274:Magnesium; D009638:Norepinephrine