| Mature cardiummyocytes are terminally differentiated cells and if once injured, can only be replaced by noncontractile, fibrous scar tissue. At present, some treatment measures, such as coronary artery bypass graft (CABG), can only recover reperfusion but can not reverse the infarcted myocardium. The loss of contractile cells will make congestive heart failure and even lead to death. Cell transplantation is becoming recognized as a important strategy to strengthen weak hearts and limit infarct growth. Studies on cell transplantation therapy to infarcted myocardium have been focused on three aspects:⑴fetal cardiac cells transplantation. ⑵ Stem cell–derived myocytes transplantation ⑶skeletal satellite cells(SCs) transplantation. The results have shown that the three methods all have some therapeutic effects, but the fetal cardiac cells and the embryonic stem cells are difficult to obtain and are limited with respect to their ability to be proliferated in culture and an immuno-rejective response after the transplantation. The use of fetal cells of myocardium and stem cells may have to face some ethical and political problems in application to human as well. So it is difficult to clinical applications. Now scientists focus on skeletal muscle which have homogeneity and similarity to myocardium in structures and functions. It is more worth paying close attention to SCs accompanying with skeletal muscle. Its action in muscle regeneration and the self-renew ability made the researchers think that SCs might be the potential cells with the abilities to treat heart infarction and improve heart function. SCs are myogenic stem cells with ability of proliferation and differentiation in mature skeletal muscle located between basal lamina and myocyte membrane. SCs are generally undifferentiated. When skeletal muscle is injured, they would be stimulated to enter the cell cycle, fuse each other, and fuse with injured muscle fibers to restore skeletal muscle function. As donor cells, SCs have many desirable traits, including the ability to be proliferated in an undifferentiated state in vitro and to remain viable in ischemic tissue. Autologous transplantation would be free of the concerns of rejection. SCs transplantation was used in muscular dystrophy(MD) firstly and then applied in heart infarction therapy. It was showed that SCs could be viable and the heart function would be improved obviously. Because this technology has an potential prospect in clinical application, many scientists are studying for it. Although there have been some achievements, but also some problems need to be solved. For examaple:⑴ quantitate graft cell survival, find a method to enhance cell survival rate; ⑵ Determine to what extent cellular engraftment exerts an active effect; ⑶Develop a technology of labelling implanted cells for a long time, ascertain the differentiated status of successfully engrafted cells; (4) determine the best implanted cell number and transplantation time, improve transplantation method, make convenient in clinical applications. For these reasons, the research is aimed to isolate,purify SCs of neonatal rats and record its growth states. Different labelling methods were used for testing their labelling rate and toxity. SCs labelled with colloidal gold were implanted to normal myocardium and infarcted myocardium. The feasibility of colloidal gold labelling method in vivo and SCs growth state were studied. The heart infarction model by cryo-injureing and the action to heart infarction by SCs transplantation were studied. The experiment included 4 parts.Methods and Results1. Primary culture and labelling methods of skeletal satellite cells of neonatal ratSkeletal muscle of limb in neonatal rat 3rd day after birth was sampled, digested by collagenase, hyaluronidase and pronase. The density gradient centrifugation was used to separate and purify the skeletal satellite cell (SC). Satellite cells were cultured in M199 and the growing states were recorded. Index of culture cell division and growth c... |
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