Nitrendipine modulates the sodium binding site of cardiac (Na,K)-ATPase.
The present study deals with the effect of calcium entry blocking agent, nitrendipine, on the rat heart sarcolemmal (Na,K)-ATPase. Nitrendipine (1 mumol/l) exerted a stimulatory effect on (Na,K)-ATPase activity. Kinetic analysis of enzyme activation by increasing concentrations of sodium in the presence of nitrendipine revealed a 67% increase in Vmax value and a decrease of the apparent Ka value to 33% of that in control. The observed influence on (Na,K)-ATPase may contribute indirectly to the calcium antagonistic effect of nitrendipine.
Institute for Heart Research, Slovak Academy of Sciences, Bratislava, CSFR.
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Dzurba
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Vrbjar
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Ziegelhoffer
D000818:Animals; D001665:Binding Sites / Q000187:drug effects; D066298:In Vitro Techniques; D009206:Myocardium / Q000166:cytology / Q000201:enzymology*; D009568:Nitrendipine / Q000494:pharmacology*; D051381:Rats; D012508:Sarcolemma / Q000187:drug effects* / Q000201:enzymology; D012964:Sodium / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000187:drug effects* / Q000378:metabolism
D009568:Nitrendipine; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase