大鼠死后肌肉电导率与腐败程度的关系

目的分析大鼠死后肌肉电导率(electrical conductivity,EC)、肉类食品腐败程度指标挥发性盐基氮(total volatile basic nitrogen,TVB-N)与死亡时间(postmortem interval,PMI)的关系,探讨EC作为尸体肌肉腐败程度评价指标的可行性,为该法用于PMI推断奠定理论基础。方法健康SD大鼠颈椎脱臼处死后,保存在28℃环境中,于死后不同时间点提取大鼠后肢肌肉组织,用去离子水制成质量浓度为0.1 g/m L的肌肉浸渍液,并测量所得浸渍液的EC值和TVB-N含量。分析EC(x_1)与TVB-N(x_2)的相关性,建立二者关系的回归方程;分析两指标与PMI的相关性,并分别建立两指标与PMI(y)关系的回归方程。结果肌肉浸渍液EC、TVB-N随PMI的变化曲线走势基本相同;EC与TVB-N呈显著直线正相关,回归方程为x_2=0.14 x1-164.91(R~2=0.982);EC、TVB-N与PMI显著相关,回归方程分别为y=19.38 x_1~3-370.68 x_1~2+2 526.03 x1-717.06(R~2=0.994),y=2.56 x_2~3-48.39 x_2~2+330.60 x_2-255.04(R2=0.997)。结论大鼠死后肌肉EC与TVB-N变化趋势一致,可以作为反映尸体肌肉腐败程度的指标,为腐败尸体PMI推断的相关研究提供方法。

Relationship between Electrical Conductivity and Decomposition Rate of Rat Post-mortem Skeletal Muscle

Objective T o analyze the relationship am ong electrical conductivity (E C ), total volatile basic nitrogen (T V B-N ), w hich is an index of decom position rate for m eat production, and postm ortem inter-val (PM I). T o explore the feasibility of E C as an index of cadaveric skeletal m uscle decom position rate and lay the foundation for PM I estim ation. Methods H ealthy Sprague-D aw ley rats w ere sacrificed by cervical vertebrae dislocation and kept at 28℃. M uscle of rear lim bs w as rem oved at different PM I, ho-m ogenized in deionized w ater and then skeletal extraction liquid of m ass concentration 0.1 g/m L w as prepared. E C and T V B-N of extraction liquid w ere separately determ ined. T he correlation betw een E C (x1) and T V B-N (x2) w as analyzed, and their regression function w as established. T he relationship be-tw een PM I (y) and these tw o param eters w ere studied, and their regression functions w ere separately established. Results T he change trends of E C and T V B-N of skeletal extraction liquid at different PM I w ere alm ost the sam e, and there w as a linear positive correlation betw een them . T he regression equation w as x2=0.14 x1-164.91 (R2=0.982). E C and T V B-N of skeletal m uscle changed significantly w ith PM I, and the regression functions w ere y=19.38 x13-370.68 x12+2526.03 x1-717.06 (R2=0.994), and y=2.56 x23-48.39 x22+330.60 x2-255.04 (R2=0.997), respectively. Conclusion E C and T V B-N of rat postm ortem skeletal m uscle show sim ilar change trends, w hich can be used as an index for decom position rate of cadaveric skeletal m uscle and provide a m ethod for further study of late PM I estim ation.