实验性心肌缺血引起的脂质过氧化反应和抗氧化剂的抑制作用

本实验采用结扎大鼠冠脉左前降支法造成心肌梗塞(MI)的动物模型,旨在观察 MI 急性期同一大鼠梗塞区和非梗塞区氧自由基引起的膜脂质过氧化反应(LPO)的时相变化。LPO 的激活程度以 LPO 的产物丙二醛(MDA)的含量及抗氧化酶超氧化物岐化酶(SOD)的活性变化作为观察指标。取材时间分别为手术后0.75、1.50,3.0、72.0小时。并在3小时实验动物组分别给予天然植物抗氧化剂 Z和 R,观察它们对 LPO 的抑制作用。实验结果表明,心肌梗塞区 MDA 呈双向时相变化,手术后3小时达到高峰。SOD 呈下降趋势。在0.75～3小时 MDA 含量升高与SOD 活性下降呈高度负相关。同时观察到所给予的天然植物抗氧化剂 Z 和 R 对 LPO有较好的抑制作用。

LIPID PEROXIDATION AND INHIBITING EFFECTS OF ANTIOXIDANTS IN EXPERIMENTALLY INDUCED MYOCARDIAL ISCHEMIA

Rat experiments were performed to describe the time course of lipid peroxida- tion(LPO) with various influence upon the heart.The contents of malondialde- hyde(MDA) and the activity level of super- oxide dismutase(SOD)were measured.In addition,the ability of two antioxidants against free radical mediated myocardial damage was evaluated.The experimental groups consisted of rats with intact hearts. rats treated in anterior descendens ramus ligation with ischemia through 45,90, inures,3 hours and 3 days.The treated rats showed characteristic alteration in biochemical parameters and the MAD level and SOD were measured.It was found that the MDA grandually increased and reached its peak value at the end of a 3-hour ligation,whereas the SOD levels decreased sharply between 45 minutes and 3 hours after ischemic insult,It was worth notice that both antioxidants had effects on the suppression of the activation of LPO.