大鼠死后视网膜细胞核DNA含量变化的图像分析

目的分析死后不同时间大鼠视网膜细胞核DNA含量变化图像，探讨视网膜细胞核DNA降解与死亡时间（PMI）的关系。方法90只成年健康雌性SD大鼠，随机分成15组，死后0—28h内（20℃），每2h提取视网膜细胞进行Feulgen-Vans染色；采用图像分析系统检测视网膜细胞核的异形指数（ID）、积分光密度（IOD）和平均光密度（AOD），并运用SPSS12．0软件对测量数据进行线性回归分析。结果视网膜细胞核AOD和IOD随死亡时间的延长逐渐下降，ID则呈上升趋势。28h内各参数变化的回归方程如下：YAOD=-0．009XAOD＋0．590，R^2=0．949，Y100=-0．097X。＋18．903，R^2=0．968，Y10=0．122X10＋2．246，R^2=0．951。结论大鼠死后视网膜细胞核DNA含量随着死亡时间的延长而呈规律性降解，并与PMI具有良好的相关性。

Image analysis for degradation of DNA in retinal nuclei of rat after death

Objective The changes of retinal nuclear DNA content in rats after death was detected and the relationship between degradation of retinal nuclear DNA and postmortem interval(PMI)was analyzed.Methods 90 healthy adult SD rats,female,weighting 250g±10g,randomly divided into 15 groups,at 20℃,the retinal cells were withdrawn every 2h within 0 to 28h after death and stained with Feulgen-Vans.Index of density(ID),Integral Optical Density(IOD) and Average Optical Density(AOD) in retinal nucleus were analyzed by image analysis system,and the obtained data were subjected to linear regression analysis by using SPSS 12.0 software.Results The results showed that in retinal nucleus,AOD and IOD were gradually declined with the along with the prolongation of PMI,while ID had an increased tendency.Within 28h after death,the regression equations were as follows: YAOD=-0.009 XAOD+0.590(R2=0.949),YIOD=-0.097 XIOD+18.903(R2=0.968),YID=0.122XID+2.246(R2 = 0.951).Conclusions It was concluded that retinal nuclear DNA after death in rats was degraded gradually and had a good correlation with PMI.