Abstract: Objective To investigate the relationship between postmortem interval（PMI） and concentration changes of components in swine vitreous humor. Methods Ninety-six porcine eyes from swine dying from acute massive hemorrhage, being randomly divided into 24 groups, were stored in dark situation, at temperature of （15±2） ℃ and humidity of（50±5）% for 2-96 hours separately. The vitreous humor was collected. Concentrations of K+, Na+, Cl- and hypoxanthine（Hx） were analyzed by automatic biochemical analyzer and ultra performance liquid chromatograph（UPLC）. The data were statistically analyzed by SPSS software. Results Linear regression analysis showed that concentrations of vitreous K+ and Hx were positively correlated with PMI（R2=0.767 and R2=0.793, respectively）. Binary linear regression showed a higher correlation for K+ and Hx with PMI estimation（R2=0.866）. PMI was not significantly correlated with vitreous Na+ and Cl- concentrations. Conclusion Vitreous K+ and Hx concentrations can be used as the objective markers for PMI estimation. The binary linear regression functions of vitreous K+ and Hx concentrations with PMI are more accurate for estimating the PMI.

Key words: forensic pathology, hypoxanthine, potassium, vitreous humor, postmortem interval, swine