恒磁场增强心肌梗死大鼠骨髓间充质干细胞移植后心脏功能改善

目的：研究恒磁场对心肌梗死大鼠骨髓间充质干细胞（bone marrow-derived mesenchymal stem cells,BMSCs）移植后心脏功能的影响。方法：取180g,9-12周龄雄性SD大鼠骨髓,以密度梯度离心分离出单个核细胞（MNCs）,于体外培养并传代培养出骨髓间充质干细胞（MSCs）。制作大鼠心肌梗死模型,将1.5×106BMSCs注射入梗死梗死区周围,分为磁场照射＋BMSCs植入组、BMSCs植入组及空白对照组。4周后处死动物,每组5只大鼠。磁场照射组用0.4 T恒磁场置于心前区30 min,每日1次,共7天。用颈动脉插管法测定心脏功能,Masson三色染色测定梗死面积,VWF VIII染色计算血管密度。结果：与对照组相比BMSCs组以及磁场组均可以显著提高左心室收缩压（LVSP）,dp/dtmax以及-dp/dtmax,减少LVEDP（P〈0.05）。但是,磁场组与BMSCs组相比LVSP,左心室内压最大上升速率（dp/dtmax）以及左心室内压最大下降速率（-dp/dtmax）增高,左心室舒张末压（LVEDP）减少（P〈0.05）。与对照组相比BMSCs组以及磁场组均可以显著提高减少心梗面积（P〈0.05）。磁场组与BMSCs组相比心梗面积减少（P〈0.05）。与对照组相比BMSCs组以及磁场组均可以显著提高增加血管密度（P〈0.05）。磁场组与BMSCs组相比血管密度增加（P〈0.05）。结论：恒磁场具有加强移植BMSCs改善心脏功能的作用。

Study on Constant Magnetic Field Enhance Transplanted Rat Bone Marrow Mesenchymal Stem Cells Improve Cardiac Function Post Myocardial Infarction

Objective： To investigate the effect of constant magnetic fields exprose on BMSCs which transplante into infarcted myocardium. Methods： Mononuclear cells were isolated from 180g ,9-12 weeks male SD rat bone marrow by density-gradient centrifugation and were cultured on fibronectin-coated plates with bovine pituitary extract. Infarct size, density of capillary and cardiac function was evaluated after BMSCs transplantation into infarcted myocardium in different groups. Results： Compared with that in the control group, both magnetic fields group and BMSCs groups had significant improvement on hemodynamic parameters （LVSP, LVEDP, ＋dP/dtmax and -dP/dtmin）. Both magnetic fields group and BMSCs groups treated MI animals showed smaller infarction size compared with that in the control animals. Capillary density increased in magnetic fields group and BMSCs groups compared with that in control treated hearts with MI. Conclusion： Constant magnetic field enhance rat bone marrow mesenchymal stem cells improve cardiac function post myocardial infarction.