大鼠急性心肌梗死的组织病理学变化及干细胞治疗

Histopathologic changes of acute myocardial infarction and stem cell therapy in rats

目的动态观察大鼠急性心肌梗死(AMI)的组织病理学变化,针对性的探讨骨髓干细胞(BMSC)治疗AMI的最佳时机和定位。方法结扎冠状动脉制作AMI模型,对术后1、2、4、6、8、10d大鼠心脏切片行HE染色,进行动态的对比观察,对心肌细胞变性坏死、急慢性炎症等病理现象做出半定量的评估。结果AMI后的细胞浸润主要集中在梗死周围区。AMI后4d内,中性粒细胞在梗死周围区的浸润显著。AMI后4d起,梗死周围区出现大量的新生毛细血管。缺血区域的心内膜下和血管周围,AMI后可以先后观察到液化性细胞溶解和残存心肌细胞存活的现象。各切片心肌组织中均未见波纹纤维。结论大鼠心脏在AMI后发生的组织病理学变化具有明显的时间和区域变化规律。AMI后的4d内,中性粒细胞显著浸润,此时的心肌局部微环境可能不适合干细胞治疗。而具有显著炎症细胞浸润和血管增生的梗死周围区,对BMSC治疗可能有特殊重要的意义。

Objective To observe dynamically the histopathological changes of rat hearts during acute myocardial infarction （AMI） for selecting the optimal time and localization of bone marrow stem cell transplantation. Methods The left coronary artery was ligated for establishing a model of AMI.The hearts were taken on day 1,2,4,6,8 and 10 after AMI,respectively,for examining the histopathologic changes including myocardial injury and post-infarction inflammatory response. Results Cellular infiltration mainly localized in border zone. Within 4 days after AMI,neutrophils infiltrated significantly in border zone,and decreased thenafter.The novel capillaries began to increase 4 days later,meanwhile the colliquative myocytolysis and survived cardiomyocytes were observed in subendocardium and peri-vessel area.Wavy fibers were not seen in any slices. Conclusion The histopathological variations of AMI have a clear character of time and location.Within 4 days of AMI,due to significant infiltration of neutrophils,local microenvironment may not be suitable for stem cell therapy. As its obvious inflammation and proliferation of capillaries,border zone may be important for BMSC transplantation after AMI.