Estimation of Postmortem Interval with Porcine Vitreous Humor in Different Environments

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.