茶色素对家兔急性心肌缺血的保护作用研究

目的观察茶色素对垂体后叶素所致家兔急性心肌缺血的保护作用。方法经心电图检查及Pit敏感性筛选，选取健康成年家兔32只，随机分为正常对照组、模型对照组、茶色素低剂量组（48mg／kg）和茶色素高剂量组（96mg／kg），每组8只。采用耳缘静脉注射垂体后叶素（pituitrin，Pit）诱发家兔急性心肌缺血。心电图监测观察注射垂体后叶素后不同时间点的Ⅱ导联心电图ST段位移及T波波幅，同时测定血压值，观察实验前后上述各项指标的变化。结果与正常对照组相比，造模后模型对照组家兔心电图出现明显的波形异常，ST段变化显著，T波倒置明显，血压升高亦显著（P〈0．01，P〈0．05）。而茶色素大、小剂量组ST段及T波的缺血性变化可显著减轻，且动脉血压明显下降（P〈0．05），但茶色素大小剂量组之间心电图变化无明显差别（P〉0．05）。结论茶色素可减轻垂体后叶素诱发的家兔心电图缺血性改变（ST段抬高、T波倒置），并能对抗血压的异常升高（P〈0．05），对家兔急性心肌缺血有一定的保护作用。

Study on protective effect of tea pigment on acute myocardial ischemia in rabbits

Objective To investigate the protective effect of tea pigment on acute myocardial ischemia induced by Pit in rabbits. Methods According to electrocardiogram （ECG） and Pit sensitiveness test , thirty - two healthy adult rabbits were selected and randomly divided into normal control group, model control group, low dose tea pigment group （48 mg/kg） and high dose tea pigment group（96 mg/kg） ,with eight rabbits in each group. In lab experiment the model of acute myocardial ischemia was induced by pituitrin（ Pit ,2.0 U/kg） injected intravenously. The locomotion of T wave and ST segment of lead Ⅱ normal ECG of rabbits were recorded, and the changed ECG and blood pressures were evaluated at different minutes after giving Pit. Results Compared with normal control group, the rabbits of model control group performed an abnormal ECG, the locomotion of T wave and ST segment of lead Ⅱ ECG changed significantly, and the blood pressure reaehed to a high level （P 〈0. 01 ,P 〈0. 05）. However, the changes of myocardial isebemia were significantly reduced in tea pigment groups and blood pressure was significantly lower than that of model control group （ P 〈 0. 05 ） , while there was no difference between high and low dose tea pigment groups in ECG （ P 〉 0. 05 ）. Conclusion The results showed that tea pigment reduced the myocardial ischemia injury induced by Pit, and antagonize the abnormal high blood pressure（ P 〈 0. 05 ）. These results demonstrated that the tea pigment possessed the protective effects on acute myocardial ischemia.