大鼠骨骼肌电导率及相关生物胺的含量变化与死亡时间的关系

Relationship between electrical conductivity and related bioamines of rat skeletal muscle and postmortem interval

目的测定大鼠死后不同死亡时间(postmortem interval,PMI)骨骼肌浸渍液电导率(electrical conductivity,EC)及蛋白质腐败降解产生的5种生物胺(尸胺、腐胺、组胺、精胺、亚精胺)的含量并分析与PMI之间的关系,更深层次的探讨EC随PMI变化的内在机制。方法将40只健康SD大鼠处死保存于25℃环境中,分别于死后即刻(0d)、1d、2d、3d、4d、5d、6d、7d不同时间点提取大鼠后肢骨骼肌组织,制成匀浆浸渍液,利用电导率仪和离子色谱仪(Ion chromatography,IC)测定肌肉组织浸渍液EC值及5种生物胺的含量,并分析EC、5种生物胺的含量变化及PMI三者之间的关系,分别建立回归方程。结果大鼠死后7d内骨骼肌组织EC随PMI的延长而逐渐增大(R2为0.96),其浸渍液中尸胺、腐胺、组胺的含量随PMI的延长而逐渐升高(R2为0.91~0.98),并且EC与尸胺、腐胺、组胺的含量变化呈线性相关(R2为0.90~0.97)。而浸渍液中精胺、亚精胺随PMI的延长变化不明显(P>0.05)。结论随着PMI的延长,浸渍液中尸胺、腐胺、组胺的变化规律与EC一致,且与PMI的相关性均较好。蛋白质腐败降解产生的含氮类小分子物质如尸胺、腐胺、组胺的变化是导致EC随PMI逐渐增大的影响因素。

Objective To determine the relationship between electrical conductivity(EC)and the content of five biogenic amines(cadaverine,putrescine,histamine,spermine,spermidine)of rat skeletal muscles and postmortem interval,and explore the mechanism of EC change with PMI.Methods 40 healthy Sprague-Dawley rats were sacrificed and stored in an environment of about 25℃,skeletal muscle tissues of rat were extracted respectively at different PMIs of 0,1,2,3,4,5,6 and 7 d,and then made into homogenized impregnation solution.The EC and five biogenic amines(cadaverine,putrescine,histamine,spermine,spermidine)in skeletal muscle impregnation solution were determined,and the relationship among EC in impregnation solution,five biogenic amines and PMI were analyzed.Results The EC in skeletal muscle tissues increased gradually with the extension of PMI(R2 was 0.96),The content of putrescine,histamine,cadaverine in the impregnation solution increased gradually with the prolongation of PMI(R2 was 0.91~0.98),there was a linear correlation between the content of putrescine,histamine,cadaverine and EC(R2 was 0.90~0.97).The changes of spermidine and spermine with the extension of PMI were non-significant(P>0.05).Conclusion With the extension of PMI,the changes of putrescine,histamine,cadaverine in the impregnation solution were consistent with EC,and the correlation with PMI was relatively good.Therefore,Changes in nitrogen-containing small molecular substances such as cadaverine,putrescine,and histamine produced by protein spoilage degradation are the important factors leading to increased EC.