The membrane effect of benfluron: modulation of the heart sarcolemmal (Na+, K+)-ATPase and Mg(2+)-ATPase activities.
The effect of Benfluron on the heart sarcolemmal (Na+, K+)-ATPase and Mg(2+)-ATPase activities was studied in crude membrane fraction as well as in purified sarcolemmal membranes isolated from rat heart. Benfluron in concentration range 10(-7) -5 x 10(-5) mol.l-1 did not exert any effect on ATPase activities studied. 10(-4) mol.l-1 Benfluron was stimulatory towards (Na+, K+)-ATPase, while Mg(2+)-ATPase activity was depressed. Kinetic analysis of interaction of Benfluron with (Na+, K+)-ATPase revealed an increase in the Vmax and decrease in the K(m) values for ATP. The possible mechanism of interaction of the drug with (Na+, K+)-ATPase is discussed.
Institute for Heart Research, Slovak Academy of Sciences, Bratislava, Slovakia.
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Dzurba
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Vrbjar
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Breier
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Ziegelhöffer
D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005449:Fluorenes / Q000008:administration & dosage / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects*; D066298:In Vitro Techniques; D007700:Kinetics; D009206:Myocardium / Q000201:enzymology; D051381:Rats; D012508:Sarcolemma / Q000187:drug effects / Q000201:enzymology; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
D004791:Enzyme Inhibitors; D005449:Fluorenes; C034234:VUFB 13468; D017301:Ca(2+) Mg(2+)-ATPase; D000254:Sodium-Potassium-Exchanging ATPase