肌肉电导率和pH两指标联用推断死亡时间

PMI estimation using electrical conductivity and pH value

目的 探讨肌肉浸渍液电导率(electrical conductivity,EC)、pH两指标联用在PMI推断上的意义.方法 SD大鼠处死后,保存在25℃环境中,于不同PMI提取大鼠后肢肌肉制备匀浆液,测定浸渍液EC和pH.分析EC、pH两指标联合使用推断PMI的意义.结果 EC、pH两指标随PMI均呈现阶段性变化:1d内,pH明显下降,EC无明显变化;2～3d,EC、pH均快速增大;4～10d,EC继续增大,而pH变化不明显.EC、pH联合使用,有助于划分PMI时段,以及特定时段内指标的优化:1d内,选择pH最佳,2～3d,EC、pH联用最佳,4～10d,选择EC最佳.结论 EC、pH联用有助于提高PMI推断的准确性.

Objective To investigate the significance to PMI estimation using combination of two parameters,electrical conductivity(EC) and pH.Methods Healthy Sprague-Dawley rats were killed kept at 25℃.Muscle samples were acquired at different PMIs and their extraction liquids were prepared for the determination of EC and pH.Then the significance to PMI estimation using combination of EC and pH was analyzed.Results Three stages were found for both EC and pH:during the first day,EC had no significant change,while pH decreased rapidly.From day 2 to day 3,both EC and pH increased rapidly with PMI.From day 4 to day 10,EC continued to increase,while pH had no significant change.Combination of the two parameters could help separate the PMI stages and choose better parameter within specific stage:Within the first day,pH was more effective.From day 2 to day 3,both EC and pH were effective.From day 4 to from day 10,EC was more effective.Conclusion Combination of EC and pH could improve the accuracy of PMI estimation.