心肌细胞移植改善心肌梗死大鼠左心室收缩功能

Assessment of the effect of cardiomyocyte transplantation on left ventricular systolic function in rats with chronic myocardial infarction by tissue velocity imaging

目的探讨心肌细胞移植对心肌梗死大鼠的左心室收缩功能的改善作用。方法将65只雄性Wistar大鼠随机分为试验组、对照组和假手术组。试验组(n=25)和对照组(n=25)均结扎冠状动脉左前降支,建立慢性心肌梗死模型。4周后,试验组于心肌梗死区与正常心肌交界处移植新生鼠的心肌细胞；对照组采用与试验组同样方式注射细胞培养液基质；假手术组(n=15)开胸后不结扎冠状动脉,不进行细胞移植。心肌梗死后4周和细胞移植后4周,均采用组织多普勒技术结合二维超声心动图测量大鼠心脏的左室收缩末期容积(ESV)、舒张末期容积(EDV)、左室前壁舒张末期厚度(LVAWD)、左室射血分数(LVEF)及短轴缩短率(FS)、左室短轴乳头肌水平测量前壁和后壁心肌收缩期峰值速度(Sm)和峰值位移(TTs),心尖四腔观测量二尖瓣环平均Sm。用免疫组织化学技术检测试验组心肌移植细胞的存活情况。结果心肌细胞移植后4周,试验组与对照组相比,EDV和ESV均显著缩小(P＜0．01),LVAWD、LVEF、FS、左室前壁和后壁Sm、TTs及二尖瓣环平均Sm均显著增加(P＜0．01)。二尖瓣环平均Sm与左室射血分数呈正相关(r=0．87,P=0．001)。免疫组织化学检测显示试验组心肌疤痕区边缘有移植心肌阳性细胞存在。结论心肌细胞移植能显著改善心肌梗死大鼠左心室收缩功能,逆转左心室重构。

Objective To probe the effect of cardiomyocyte transplantation on left ventricular systolic function in Wister rats with chronic myocardial infarction. Methods Sixty-five male Wister rats were randomized into sham operated group （n = 15）, trial group （n = 25） and control group （n = 25）. Chronic myocardial infarction model was induced successfully both in the trial and control groups by ligating the left anterior descending artery. Four weeks later, the animals in trial group received neonatal cell transplantation in the peri-infaret region and those in control group only received culture medium. The animals in sham-operated group were only subjected to open-chest procedure. LVESV, EDV, LVAWI）, EF and FS, the peak systolic velocity （Sm） and maximum systolic displacement （TTs） at middle segments of anterior and posterior wall of LV, the mean Sm of mitral annulus were measured in 3 groups by tissue velocity imaging （TVI） and two-dimensional eehoeardiography （2DE） before and 4 weeks after cell transplantation. Histological study was used to evaluate the viability of transplanted eardiomyoeytes. Results Four weeks after cell transplantation, compared with the values of the control group, the LVESV and LVEDV were significantly decreased （P〈0.01）, the values of LVAWD, LVEF, FS, the Sm and TTs at middle segments of LVAW and LVPW were significantly increased （P〈0. 01） in the trial group. There was good correlations between the mean Sm of mitral annulus and LVEF （r= 0. 87, P = 0.01）. Histological study revealed that transplanted neonatal eardiomyoeytes were detected either in or near the peri-infaret region of the host heart in the trial group. Conclusion Neonatal eardiomyoeyte transplantation could significantly improve left ventricular systolic function in chronic myocardial infarction rats.