青蒿琥酯钠对体外大鼠红细胞膜钠-钾交换ATP酶的抑制

体外测定青蒿琥酯钠(SA)对大鼠红细胞膜Na~( )-K~( )-交换ATP酶活性的影响.方法:在反应系统中分别加入不同浓度的SA(0,0.5,1,5和10 μmol·L~(-1)),通过测定反应系统中释放的无机磷含量,计算酶活性.结果:随着SA浓度(O,0.5,1,5和10 μmol·L~(-1))的增高,对Na~( )-K~( )-交换ATP酶活性的抑制作用也随之增强,抑制率分别为15％,29％,46％和75％.将底物ATP浓度增加为125,250,375和500 μmol·L~(-1),进行了酶的动力学测定.用直线回归分析作Eadie-Hofstee动力学曲线,结果表明,SA对该酶的抑制作用为竞争性抑制.结论:提示SA可影响宿主红细胞膜的离子转运及膜的功能.

Inhibition of sodium artesunate on rat erythrocyte membrane Na( )-K( )-exchanging ATPase in vitro

To study the effects of sodium arte-sunate ( SA ) on Na( )-K( )-exchanging ATPase activity of rat erythrocyte membrane in vitro. METHODS: SA of different concentrations (0, 0. 5, 1, 5 and 10umol.L-1) were added respectively in the reaction system. The Na( )-K< )-exchanging ATPase activity was calculated by measuring the amount of inorganic phosphate released in the reaction system. RESULTS: Along with the increase of SA concentration (0, 0. 5, 1,5 and 10umol,L-1), the Na( )-K( )-exchanging ATPase activity decreased, the inhibitory rates were 15 % , 29 % , 46 % , and 75 % , respectively. Increasing the concentration of substrate ATP to 125, 250, 375 and 500umol .L-1 and determining the kinetics of enzyme. Making the Eadie-Hofstee kinetic curve by linear-regression analysis. The result revealed that the inhibitory effect of SA on the enzyme was competitive. CONCLUSION: SA affected the ion transfer of host erythrocyte membrane and membrane function.