心肌肌钙蛋白T在家兔缺血心肌中的表达及其死后稳定性

目的 探寻心肌肌钙蛋白T（cTnT）在家免缺血心肌中的表达规律及其死后稳定性．并对其在法医学实践中诊断早期心肌缺血的应用价值进行评价。方法用冠状动脉结扎法建立家兔急性心肌缺血模型．应用免疫组织化学法、图像分析和统计学处理系统,检测死后cTnT表达情况,并对实验组和对照组cTnT的表达进行比较。结果缺血区心肌组织可见明显不规则灶状、片状cTnT缺失区,间质呈阴性表达。在4℃放置．随放置时间延长,正常和缺血心肌组织cTnT阳性表达均有减弱趋势,至14d时均完全缺失。但仅在4℃放置1～7d内,缺血心肌和正常心肌标本之间cTnT阳性反应具有显著性差异。结论cTnT的免疫组化表达用于认定死后4℃放置的尸体是否有死前心肌缺血时．宜在7d以内进行。

Expression of cTnT in rabbit hearts during myocardial ischemia and its postmortem stability

OBJECTIVE: To study the postmortem stability of cTnT as well as its expression alteration, and to evaluate it in the diagnosis of early myocardial ischemia in forensic practice. METHODS: Animal model of early myocardial ischemia was established by rabbit coronary artery ligation. The expression of cTnT in myocardium at different postmortem intervals was detected using immunohistochemistry and analyzed using imaging technique and statistics. The results were then compared between the experimental and control groups. RESULTS: In ischemic myocardium, the expression of cTnT showed prominent focal or flaky depletion in myocardial cytoplasm with no expression detected in interstitium. The expression level showed a linear decrease with prolonged postmortem interval, and disappeared completely on day 14 after death while stored at 4 degrees C. However, there were significant differences in the expression levels of cTnT between experimental and control groups from day 1 to day 7 after death. CONCLUSION: Immunohistochemical detection of cTnT for diagnosis of early myocardial ischemia in corpses stored at 4 degrees C must be performed within 7 days after death.