[Relationship between Myofibril Fragmentation Index and Postmortem Interval].

ABSTRACT

OBJECTIVES: To study the relationship between myofibril fragmentation index （MFI） of human skeletal muscle and postmortem interval （PMI）. METHODS: The protein concentrations of human right biceps brachii muscle and right quadriceps femoris muscle were obtained at different PMI, and detected at room temperature by biuret method. The MFI of skeletal muscle at 540 nm was measured by ultraviolet spectrophotometer. Regression analysis was performed with time of death as independent variable （x） and MFI as dependent variable （y）. RESULTS: In early PMI, the MFI of human skeletal muscle increased obviously according to the prolongation of PMI, and peaking by 12 h and then tended to steady. Within 12 h after death, the regression equations of right biceps brachii muscle and right quadriceps femoris muscle were y=32.660+3.227 x（r=0.987 9） and y=32.380+3.495 x（r=0.983 9）, respectively. CONCLUSIONS: There's high correlation between MFI and PMI. Combining with forensic practice, MFI can be used for the estimation of early PMI （especially in 12 h）.