干细胞动员对梗死心肌结构及功能的影响

Influence of bone marrow stem cells mobilization on basic structure and heart function in myocardial infarction rats

目的探讨干细胞动员对心肌梗死后心肌基本结构和心功能的影响。方法结扎Wistar大鼠左冠状动脉制作急性心肌梗死(AMI)模型66只,随机分动员组33只和对照组33只,动员组应用基因重组人粒细胞集落刺激因子(rhG-CSF)10μg·kg-1·d-1皮下注射共7 d,对照组皮下注射生理盐水7 d。建模后两组分别在24 h、2周和4周杀死大鼠,取出心脏,HE染色观察细胞形态特征、结构,梗死面积和心肌组织CD34阳性表达,并检测术后4周时动员组和对照组大鼠的血流动力学指标、心功能参数。结果动员组梗死区可见大量CD34浸润,梗死面积明显减小;梗死程度较对照组减轻,术后4周,动员组缺血心肌的基本结构得到保护,组织结构排列基本处于有序状态,左心功能恢复明显优于对照组,表现在SBP、DBP、LVSP、LV±dp／dtmax均高于对照组(P<0．05),LVEDP明显低于对照组(P<0．05)。结论干细胞动员能促进干细胞归巢梗死心肌并分化为心肌细胞样细胞,保护缺血心肌的基本结构,明显改善大鼠心肌梗死后的心脏功能。

Objective To investigate the influence and heart function in myocardial infarction rats. Methods of bone marrow stem cells mobilization on basic structure Left anterior descending coronary arteries were ligated to produce acute myocardial infarction（ AMI ） model in 66 wistar rats which were randomized into mobilized group（ n = 33） and control group（ n = 33 ）, Mobilized group used rhG-CSF（ 10μg·kg^-1· d^- 1 ） in hypodermic injection for 7 days and control group used NS. Hearts were harvested in the 24th hour, 2nd and 4th week after AMI modeling for histopathological examination, Immupohistochemisty and HE stain were used to detect infiltration of CD34 cclls and the regeneration of myocytes in the part of ischemia. Infarct area were measured. 4 weeks after the modeling, the blood flow dynamic index and coefficient of heart function of each rat were detected by the biofunction laboratory system（BL-420E system） Results Infarct area in mobilized group was obviously tess than in AMI group There were a great number of monocytes infiltrating with CD34 expresion by immunohistochemisty in myocardial infracted zone in mobilized rats, The necrosis in mobilized group was significantly slighter than that in control group and only limited to subendothelium. SBP,DBP, LVSP and LV ＋ dp/dtmax in mobilized group were higher than those of AMI group（P 〈 0.05） ; LVEDP in mobilized group was significantly lower than those of AMI group（ P 〈 0.05）. Conclusion In rat MI model,G-CSF can mobilize bone marrow stem cells to migrate to infarcted zones and differentiate to cardiomyocyte-like cells. Mobilization treatment can prevent collagenous fibres from fusing,pretect ischemic myocardial structure, decrease infarct size, improve heart function.