Mode of inhibition of activity of Na+-K+-stimulated adenosine triphosphatase by indomethacin.
1. The activity of the overall Na+-K+-ATPase reaction was inhibited by indomethacin in vitro. 2. The K+-NPPase activity was also inhibited by indomethacin. 3. The activity of Na+-dependent phosphorylation of Na+-K+-ATPase was activated by indomethacin. 4. Indomethacin required for 50% inhibition of K+-NPPase activity was 0.4 mM. 5. Inhibition mode of indomethacin for both the substrate and K+ in K+-NPPase reaction was competitive type. 6. The Ki values for indomethacin for the substrate and K+ in K+-NPPase reaction were 0.4 and 0.24 mM, respectively. 7. Inhibitory effect of indomethacin on K+-NPPase was reversible.
D009597:4-Nitrophenylphosphatase / Q000378:metabolism; D000818:Animals; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology*; D007700:Kinetics; D010766:Phosphorylation; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*; D013552:Swine; D013997:Time Factors
D009597:4-Nitrophenylphosphatase; D000254:Sodium-Potassium-Exchanging ATPase; D007213:Indomethacin