兔死后角膜内皮细胞核DNA降解随死亡时间变化规律

DNA degradation principles of cornea endothelial cells in dead rabbits

目的研究兔死后角膜内皮细胞核DNA降解与死亡时间的关系。方法应用单细胞凝胶电泳(SCGE)技术结合荧光显微镜和专业的计算机图像分析技术,检测27只家兔死后48h内不同时间点角膜内皮细胞核DNA降解情况。结果家兔死后角膜内皮细胞产生彗星现象,彗星样细胞出现率于兔死后6h开始逐渐增加。死后6～18h彗星样细胞出现率增加缓慢,死后24～36h出现率上升较快;死后36～48h彗星样细胞出现率上升缓慢,但仍始终保持在较高的水平上(M1>85.4%),其回归方程为y=-0.0096x2+2.4548x+5.7964,与死亡时间呈正相关(R2=0.9743)。结论家兔死后角膜内皮细胞彗星样细胞出现率随死亡时间增加而逐渐增加。

Objective To study changes of DNA degradation and its relationship with the postmortem interval.Methods DNA degrdation in cornea epithelia cells of 27 rabbits with different interval postmortem between 0h and 48h were detected by single-cell gel electrophoresis（SCGE）and oberserved by fluorescent microscope connected with auto-analysis-image system.Results The Comet-like cells appeared and the percentage of comet-likel cells began to increase after 6h postmortem interval,it showed an increase of slow rate during 6～18h postmortem interval,occured rapidly during 24～36h postmortem interval,and increased slowly during 36～48h postmortem interval,but still remained at high levels（M185.4%）,The regression equation is y=-0.0096x2＋2.4548x＋5.7964,the degradation rate of nuclear DNA was positively correlated with the length of PMI（R2=0.9743）.Conclusion The percentage of comet-likel cells of Cornea endothelial cells in dead Rabbits increased gradually with the PMI.