低温环境下家兔急性心肌缺血时心肌细胞形态学的变化

Myocardial Cell Morphological Changes of Rabbits with Acute Myocardial Ischemia in Low Temperature Environment

目的:探讨低温环境下家兔急性心肌缺血时心肌细胞形态学的变化规律。方法:将112只家兔分为实验组和对照组,每组各56只。实验组是结扎家兔左冠状动脉左室支中下1/3处建立急性心肌缺血模型,对照组是开胸但不阻断冠状动脉血流。两组家兔均在自然低温环境下(10℃、5℃、0℃、-5℃)暴露30 min、60 min后做心肌HE染色,观察心肌细胞形态学的变化情况。结果:10℃和5℃自然低温环境下对照组心肌细胞形态学无明显变化。当环境温度从0℃降至-5℃的过程中,对照组心肌纤维从排列较整齐逐渐变为心肌纤维拉长、排列疏松,心肌间质细胞水肿。当环境温度从10℃降至-5℃的过程中,实验组心肌纤维逐渐从拉长,排列疏松至排列呈波浪状改变并有部分心肌纤维断裂,心肌细胞间质水肿,小血管明显淤血。结论:随着环境温度的下降,可使心肌细胞变性损伤,实验性急性心肌缺血家兔的心肌细胞损伤更加明显。提示低温环境的变化是心肌细胞损伤的重要因素,对已有缺血改变的心肌细胞损伤更严重。

Objective：To study myocardial cell morphological changes of rabbits with acute myocardial isehemia in low temperature environment. Method：ll2 rabbits were divided into experimental group and control group, each group had 56 rats.The experimental group were ligated at 1/3 of the left ventricle branch of left coronary artery to establish the model of acute myocardial ischemia, while the control group were given thoracotomy without occluding the coronary artery blood flow.Myocardial HE staining was done after two groups of rabbits exposed to 30 rain, 60 min in the natural low temperature （10 ℃, 5 ℃, 0 ℃, -5℃ ）, and then myocardial cell morphological changes were observed.Result：There was no significant changes of myocardial cell morphology of the control group in 10 ℃and 5 ℃ temperature.When the environment temperature dropped gradually from 0 ℃ to -5 ℃, myocardial fibers of the control group had a gradually changed process：neatly arranged, elongated, loosely arranged, and then caused the edema of myocardial interstitial cell.When the environment temperature dropped gradually from 10 ℃ to -5 ℃, myocardial fibers of the experimental group also had a gradually changed process：elongated, loosely arranged to permutations of wavy change, meanwhile, some myocardial fibers broke and caused the edema of myocardial interstitial, and the congestion of small blood vessels was visible as well.Conclusion：Along with the decrease of environmental temperature, the degeneration and injury of myocardial ceils happened gradually, and myocardial cell injury of experimental rabbits with acute myocardial ischemia was more obvious.It shows that low temperature environmental change is the important factor of myocardial cell injury, which displayes more seriously to myocardial cells with ischemic changes.