| Background: Coronary heart disease(CHD)is a common clinical disease in the middle-aged people, especially the loss of myocardial cells and the formation of myocardial scars caused by myocardial infarction(MI) are major factors affecting cardiac function. At the present, the therapeutic methods on MI including drugs, percutaneous coronary intervention(PCI) and coronary artery bypass graft(CABG) and so on, are considered to have some curative effects on CHD. But all these methods can't replace the necrosed myocardium which is not able to regenerate. Recently, the new techniques of cell and tissue engineering have enabled the purification, culture and proliferation of muscle cells in vitro, and these muscle cells can be transplanted into infarcted myocardium to proliferate and differentiate so as to replace the necrosed myocardium and prevent ventricular remodeling and improve cardiac function. Among these muscle cells, skeletal muscle stem cell(satellite cell, SC) plays an important role in cell transplantation.Objective: The study aims were trying to elucidate how the skeletal muscle SC interact with vascular endothelial growth factor(VEGF) after the transplantation of SCs into infarted myocardium and affect the ventricular remodeling and cardiac function. Up to now, there are few reports on the relationship between skeletal muscle SC and VEGF.Methods:Forty-five Wistar rats, aged 2-3 months(male 23,female 22), were randomly divided into three groups(15 rats/each group):a sham operation(SO) group, a myocardial infarction(MI) group and MI group with transplantation of SC(SCT). MI was induced by left anterior descending coronary artery(LAD) ligation in the MI group and SCT group. Meanwhile, skeletal muscle SCs of the SCT group rat's hind limb were procured by the two-step method of collegenase-I and trypsin, and were subject to primary as well as secondary culture in vitro.These cells were autologously transplanted into the ischemic myocardium between myocardial infarction and normal myocardium by injection at 2 weeks after LAD ligation. 4 weeks later, cardiac function in all groups was evaluated by polygraph system, and ventricular weight and ventricular weight index were examined byelectron balance. The expression of VEGF protein and capillary density in the ischemic myocardium were demonstrated by immunohistochemical method, and the expression of VEGF mRNA in the ischemic myocardium were detected by reverse transcription-polymerase chain reaction(RT-PCR).The differentiated myofibers from SCs in the infarcted site were observed by pathologic examination and immunohistochemical method.Results:1. Skeletal muscle SCs were procured, cultured and proliferated in vitroThe two-step method of collegenase-I and trypsin was suitable for collection of skeletal muscle SCs. The cells showed high proliferative ability in the proliferative media and could form myotubes in differentiation media. SCs were weak positive and myotubes were strong positive by immunocytochemical staining with myosin.It confirmed the cultured cells were SCs.2. Changes of cardiac structure and function in rats(1) Ventricular remodeling in rats with MILeft ventricular weight(LVW), right ventricular weight(RVW), LVW/BW(body weight) and RVW/BW were significantly increased in the MI group and SCT group compared with the SO group(P<0.01 or 0.001). But the transplantation of SCs into the ischemic myocardium(SCT group) could significantly decrease LVW, LVW/BW and RVW/BW compared with MI group(P<0.01, 0.001 and 0.05)．(2) Changes of hemodynamic parameters and cardiac functionCompared with the SO group, systolic blood pressure(SBP),diastolic blood pressure(DBP),mean artery pressure(MAP),left ventricular systolic pressure (LVSP) and ±dp/dtmax were markedly decreased(P<0.05 or 0.01 or 0.001) and left ventricular end-diastolic pressure(LVEDP) was markedly increased(P<0.001) in the MI group and SCT group. But the transplantation of SCs into the ischemic myocardium (SCT group) can significantly increase ±dp/dtmax and decrease LV...
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