不同环境中应用猪眼玻璃体液成分浓度变化推断死亡时间的研究

Estimation of Postmortem Interval with Porcine Vitreous Humor in Different Environments

目的 研究在不同环境中大出血死亡猪眼玻璃体液成分变化及其与死亡时间(postmorteminterval,PMI)的关系。方法 放血处死家猪后取192只猪眼随机分为A、B两组,分别在避光、温度(15±2)℃、湿度(50±5)%的空气中以及浸没于环境温度为(15±2)℃双蒸水的条件下放置2～96 h,采集玻璃体液,运用全自动生化检测仪、超高效液相色谱分析仪(Ultra Performance Liquid Chromatography,UPLC)检测K+、Na+、Cl–及次黄嘌呤(hypoxanthine,Hx)浓度;采用SPSS13.0统计软件对检测数据进行回归分析。结果 眼球置于空气中时,玻璃体液中K+、Hx与PMI相关性较高,回归方程为:PMI=-11.467+1.954[K+]-0.017[K+]2+0.511[Hx](R2=0.858);眼球置于双蒸水时,玻璃体液中Na+、Cl–与PMI相关性较高,回归方程为:PMI=144.439-1.636[Na+]+0.007[Na+]2-0.961[Cl-]+0.005[Cl-]2(R2=0.622)。结论 玻璃体液K+、Hx浓度变化可作为推断死后位于空气中的尸体较为稳定的指标;玻璃体液Na+、Cl–浓度变化可能对死后抛入淡水尸体的PMI推断具有参考价值。

Objective To investigate the relationship between postmortem interval（PMI） and porcine vitreous potassium and hypoxanthine in death due to acute massive hemorrhage under different environmental conditions.Methods 192 porcine eyes from pigs die of acute massive hemorrhage were divided randomly into group A and group B,which were put in the dark environment with（15±2）℃,（50±5）% humidity or kept in double distilled water from 2h to 96h,and the concentration of potassium,sodium,chlorine and hypoxanthine were analyzed by automatic analyzer and Ultra Performance Liquid Chromatography（UPLC）.The data were statistically processed by SPSS13.0 software.Results Regression analysis showed that concentration of vitreous potassium and hypoxanthine of porcine eyes kept in air were positively correlated with PMI,and the regression equations was PMI=-11.467＋1.954[K＋]-0.017 [K＋]2＋ 0.511[Hx]（R2=0.858）;however,the concentration of vitreous sodium and chlorine of porcine eyes kept in double distilled water were positively correlated with PMI,and the regression equations was PMI=144.439-1.636[Na＋] ＋0.007 [Na＋]2-0.961 [Cl-]＋0.005 [Cl-]2（R2=0.622）.Conclusion Vitreous potassium and hypoxanthine of corpses kept in air may be used as relatively objective parameter for PMI estimation,and the vitreous sodium and chlorine may be used for estimating PMI after corpses hurled in fresh water.