心肌缺血再灌注损伤时心肌肌球蛋白ATP酶活性的改变

A Study on Changes of Myosin ATPase Activities in Cardiac Ischemic Reperfusion Injury of Rabbit

目的 探讨心肌缺血再灌注损伤时心肌肌球蛋白 ATP酶活性的改变。方法 从正常兔及心肌缺血再灌注损伤模型兔心肌中提取肌球蛋白 ,根据酶反应 ATP分解释放的无机磷含量分别检测 Ca2 + 激活的肌球蛋白ATP酶的米氏常数 (Km)值及最大反应速度 (Vmax) ,并对两组蛋白酶活性进行比较。结果 对照组兔心肌肌球蛋白ATP酶的 Vmax为 (1.15± 0 .17)μm ol/ (mg· m in)、Km 为 (5 .4 3± 2 .18) mm ol;实验组心肌肌球蛋白 ATP酶的 Vmax为 (1.17± 0 .2 1)μmol/ (mg· min)、Km 为 (6 .0 2± 2 .0 1) m mol,两组心肌酶活性无显著性差异 (P>0 .0 5 )。结论 心肌缺血再灌注损伤时 ,肌球蛋白

Objective To investigate the changes of myosin ATPase activities in cardiac ischemic reperfusion injury of rabbit. Methods A convenient method was adopted to purify the myosin from the left ventricle of normal rabbit heart and of cardiac ischemic reperfusion injured rabbit heart. The michaelis constant (K m) and maximum velocity(V max) values of Ca 2+-activated ATPase were determined from the rate of Pi release in enzymatic reaction. The myosin ATPase activities of normal group and ischemic group were compared. Results The myosin ATPase activities of the control group were V max:(1.15±0.17) μmol/(mg·min), K m:(5.43±2.18) mmol and those of ischemic group were V max:(1.17±0.21) μmol/(mg·min), K m:(6.02±2.01) mmol. There was no significant difference between the two groups(P>0.05). Conclusion This modelling animal experiment showed that the myosin ATPase activities were unchanged in cardiac ischemic reperfusion injury.