高海拔地区多脏器功能不全综合征大鼠心肌细胞凋亡情况的观察

Apoptosis in heart of multiple organ dysfunction syndrome rats at high altitude

目的 :对比在不同高原梯度多脏器功能不全综合征大鼠心肌细胞凋亡情况。方法 :分别在兰州梯度(海拔 15 10m)及马汉山梯度 (海拔 3 90 0m)建立大鼠两次打击MODS模型 ,分别在术后 3h、6h、12h、2 4h处死大鼠 ,取心肌标本 ,分别用DNA琼脂糖凝胶电泳、流式细胞测量法及TdT介导的dUTP缺口末端标记法 (TUNEL)检测大鼠心肌细胞凋亡。用透射电镜观测心肌细胞的超微结构。结果 :在马汉山梯度发生MODS的大鼠心肌中检测出凋亡特有的DNA梯形条带 ,流式细胞仪PI染色法呈现出典型的亚二倍体峰 ,细胞凋亡率高于兰州梯度的大鼠 (P <0 0 1)。TUNEL法测量在马汉山梯度发生MODS的大鼠心肌中出现阳性反应。用透射电镜观测马汉山梯度心肌细胞出现典型的凋亡小体。结论 :高海拔地区发生MODS的大鼠心肌细胞凋亡发生率较高 。

AIM: To study apoptosis in heart of multiple organ dysfunction syndrome (MODS) rat at high altitude. METHODS: The two-hit model of MODS rat was used at two different altitude(1 510 m, 3 900 m). Hemorrhage was induced in Wistar rats by catheterizing the femoral artery until a mean arterial pressure was 35 mmHg and maintained for 1 hour. Rususcitation was performed with lactated Ringer′s solution at 24 h after hemorrhage, cecal ligation and puncture(CLP) was performed .Then rats were killed at 3 h,6 h,12 h and 24 h after CLP, and myocardium sample was excised and stored in liquid nitrogen. Apoptosis in heart was determined by DNA agarose gel electrophoresis, flow cytometry(FCM), transmission electron microscope(TEM) and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling(TUNEL). RESULTS: The special ladder pattern for apoptosis was seen in myocardium sample at high altitude(3 900 m) group.The apoptotic rate in myocardium was higher in high altitude(3 900 m) group than that in lower altitude(1 510 m) group( P <0.01).TUNEL showed that there were positive cells in myocardium in high altitude(3 900 m) group. Apoptotic body was also seen in myocardium in high altitude(3 900 m) group by TEM. CONCLUSION: Apoptosis was induced in myocardium of MODS rats at high altitude, which might play a role in heart failure. The environment of high altitude accelerates the impairment of myocardium in MODS rats.