The interaction between calcium and the activation of Na+, K+-ATPase by noradrenaline.
The interaction of noradrenaline, various cation chelators and calcium on Na+, K+-ATPase from rat cerebral cortex plasma membranes was studied. It was shown that chelation of inhibitory cations by EGTA, EDTA and dipyridyl activated Na+, K+-ATPase to the same extent as noradrenaline but at higher concentrations; increasing concentrations of EGTA depressed the activation by noradrenaline; calcium in the form of a calcium-EGTA buffer depressed Na+, K+-ATPase at physiological concentrations; the inhibition of Na+, K+-ATPase by calcium is dependent on the magnesium concentration in the assay and the inhibition by calcium was partially reversed by noradrenaline.
Haag
M
M
Gevers
W
W
Böhmer
R G
RG
D000818:Animals; D002118:Calcium / Q000494:pharmacology / Q000502:physiology*; D002147:Calmodulin / Q000494:pharmacology; D002462:Cell Membrane / Q000201:enzymology; D002540:Cerebral Cortex / Q000201:enzymology; D002614:Chelating Agents / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D066298:In Vitro Techniques; D008274:Magnesium / Q000502:physiology; D009638:Norepinephrine / Q000494:pharmacology*; D051381:Rats; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013053:Spectrophotometry
D002147:Calmodulin; D002614:Chelating Agents; D000254:Sodium-Potassium-Exchanging ATPase; D008274:Magnesium; D002118:Calcium; D009638:Norepinephrine