中文摘要：

目的观察停跳与不停跳两种心脏状态下经心肌注射骨髓间充质干细胞（MSCs）后全身细胞的分布。方法雄性猪的骨髓间充质干细胞用超顺磁铁纳米颗粒标记。雌性猪心梗后1周随机分为4组。第1组为停跳心脏细胞注射组（n=6），体外循环后心脏停跳，标记的细胞（1×10^8）经心肌注入心梗周边区。第2组为不停跳心脏细胞注射组（n=6），相同的细胞在跳动下心脏经心肌注入心梗周边区。第3组停跳心脏对照组（n=6）和第4组不停跳心脏对照组（n=6）中，相同剂量的生理盐水分别在停跳和不停跳心脏状态下经心肌注入心梗周边区。3d后，体内细胞分布通过核磁共振的T2＊变化及Y染色体性别决定区基因（SRY基因）的实时定量PCR检测来评价。结果细胞可以在心、肾、脾、肺和肝中检测到。1、2组中大部分的注射细胞滞留在心脏，并且1组中心脏细胞的滞留较2组多（T2＊改变：22．3±2．2比17．00±0．84；SRY gene：0．150±0．062比0．072±0．003）。结论在未来的临床实验中，在心脏停跳状态下经心肌注射骨髓间充质干细胞将是一种最适合的方法。

英文摘要：

Objective To investigate the distribution of intramyocardially injected cells in different heart status （arresting or beating） in a porcine myocardial infarction （MI） model. Methods Bone marrow （BM） mesenchymal stromal cells （MSCs） were obtained from male swine and labeled with iron oxide during culture. One week after creation of MI in female swine, the survivals were randomly divided into 4 groups. Cardiopulmonary bypass was set up to arrest heart ,and then labeled cells （ 1 × 10^8 ） were intramyocardially injected into the borderline of infracted zone in group 1 （ n = 6 ）. Same volumes of cells were grafted in the beating heart in group 2 （n =6）. In groups 3 and 4,the same volume of.saline was injected in either arresting or beating heart （ n = 6 respectively ）. Three days later, cell distribution was assessed by T2 ＊ change with magnetic resonance imaging and sex-determining region on Y-chromosome （SRY） with quantitive polymerase chain reaction. Results The cells were identified in heart, spleen,lung and liver. Most of injected cells were localized in the myocardium in groups 1 and 2, however, and the number of detained cells was more in group 1 （ T2 ＊ change： 22.3 ± 2.2 versus 17.00 ± 0.84 ; SRY gene ： 0. 150 ± 0. 062 versus 0. 072 ± 0. 003 ）. Conclusion The intramyocardial injection in the arresting heart could be an optimal approach to deliver the BM MSCs for the future clinical trials.