VEGF在家兔缺血心肌中的表达及其死后稳定性研究

目的观察心肌中VEGF在死后一定时间的稳定性及表达的变化规律，评价其对死后诊断机体早期心肌缺血的作用。方法用冠状动脉结扎法建立家兔急性心肌缺血模型，应用SP法染色、图像分析和统计学处理系统，检测缺血心肌细胞内VEGF阳性表达面积和强度，并对VEGF在死后不同时间的稳定性进行比较。结果VEGF在缺血心肌组织中，见灶性或成片心肌细胞强阳性表达，部分细胞呈阴性或弱阳性表达，血管内皮及平滑肌细胞表达弱阳性，间质表达阴性；在4℃放置，随时间延长，缺血心肌组织VEGF阳性表达有减弱趋势，至10d时缺血心肌组织仍可见VEGF在少许心肌细胞胞浆内呈弱阳性表达。在4℃放置10d以内，缺血心肌和正常心肌标本之间VEGF阳性表达具有极显著性差异。结论VEGF能耐受一定程度自溶及腐败的影响，其免疫组化检测对于判断死后4℃放置10d以内的尸体是否出现过心肌缺血具有一定意义。

A study on the expression of VEGF in ischemic rabbit hearts and its postmortem stability

Objective To observe the stability and the change pattern of VEGF expression in myocardium in varied postmortem periods,and to evaluate its usefulness in diagnosis of early myocardial ischemia after death.Methods An animal model of early myocardial ischemia was established by ligating coronary artery of rabbit,immunohistochemistry(SP protocol),image analysis technique and statistical analysis system are applied to detect and compare the area and intensity of expression of VEGF in cardiocytes,and its stability in different postmortem perieds.ResultsIn ischemic myocardium,VEGF shows foci or sheets of intense positive staining in cardiocytes,with negative or weak staining in some cells.There was weak staining in vascular endothelial cells and smooth muscle cells,but no staining in interstitium.When ischemic myocardium stored at 4℃,the staining of VEGF became weaker with time delay,but there was weak staining in a fraction of cardiocytes even 10d after death.There was significant difference in the intensity of VEGF staining between ischemic and normal postmortem myocardium from 1 to 10d.Conclusion VEGF can withstand a certain degree of autolysis or putrefaction,and the immunohistochemical staining of it is valuable in the diagnosis of early myocardial ischemia in corpses stored at 4℃ for 1~10d after death.