Magnetic Resonance Spectroscopy of Rat Skeletal Muscles. An Application to the Estimation of the Postmortem Interval.

大鼠骨骼肌的磁共振波谱分析。

• 批准号: 05670402
• 负责人: HIRAKAWA Keiko
• 金额: $ 1.47万
• 依托单位: Nippon medical School
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05670402/
• 关键词: Postmortem changes; Rigor mortis; Skeletal muscle; Magnetic resonance spectroscopy; Energy metabolism; Postmortem interval; pH; phosphorus

It is considered that the fall in ATP content is directly related to the onset of rigor mortis. Therefore, ATP content in the skeletal muscle is a factor which has been considerd to be of value in estimating the postmortem intaerval. Using conventional techniques, however, it is difficlt to quantify high phosphate compounds accurately in the biological materials. The ^<31>P-MRS can be used to measure ATP,phosphocreatine (PCr) and inorganic phosphate (Pi) very rapidly and noninvasively in biological tissues. Intracellular pH value can also be determined using the chemical shift of Pi. The operation and the interpretation of the spectrum is relatively simple, so it is easy to master the technique. For the purpose of evaluate the possibility of the application of ^<31>P-MRS to the estimation of the postomortem interval, we analyzed high energy phosphate compounds in the skeletal muscles of the dead rats using the ^<31>P-MRS and examined the association between the analytical results and p … More ostmortem intervals. The animals were killed in cases of strangulation, nitrogen asphyxia, drowning, or fatal intoxications due to CO gas, methamphetamine, cocaine, ethanol or KC1. ^<31>P-MRS was performed using the surface coil technique up to 4 hours after death. Signal intensities of the peaks in the spectra and the pH values in the tissues were calculated. Correlation analysis was used to estimate the strength of the association between the postmortem interval and the content of ATP,PCr and Pi, and the pH value in the tissues. Regression analysis was also used to estimate the postmortem interval from ^<31>P-MRS data. In any mode of killing, PCr and ATP decreased after death, whereas Pi increased with time. The pH value was decreased linearly in the early stage after death. In the tissues of the rats killed in the relativeabsence of muscular activity before death, the reduction of the PCr and ATP content was relatively slow. When the rats died following hard exercise, struggle or convulsions, the fall in PCr and ATP content was accelerated. Among all the mode of killing, there was little variation in the decreasing rate of the pH value. In any mode of killing, all ^<31>P-MRS data indicated significant correration with postmortem interval. There was a close relation between the pH in the tissue and postmortem interval. Least squares regression analysis to estimate the postmortem interval from the ^<31>P-MRS data was successful. R squared values calculated were high, althogh the data points showed some degree of scatter. Our present results suggest that ^<31>P-MRS data can be used as a means to estimate the time of death. Especially, in the early stage after death, the pH value is generally ragarded as providing one of the most reliable ways of estimating the time of death. Less

认为ATP含量的下降与尸僵的发生有直接关系。因此，骨骼肌中的ATP含量被认为是估计死后时间间隔的一个有价值的因素。然而，使用传统的技术，很难准确地定量生物材料中的高磷酸盐化合物。^<31>P-MRS可用于非常快速和无创地测量生物组织中的ATP，磷酸肌酸（PCr）和无机磷酸盐（Pi）。细胞内的pH值也可以用Pi的化学位移来确定。光谱的操作和解译相对简单，易于掌握。为了评估^<31> p - mrs应用于死后时间估计的可能性，我们使用^<31> p - mrs分析了死亡大鼠骨骼肌中的高能磷酸盐化合物，并检验了分析结果与p - mrs之间的关系。这些动物因一氧化碳气体、冰毒、可卡因、乙醇或KC1导致的窒息、氮窒息、溺水或致命中毒而死亡。^在死亡后4小时使用表面线圈技术进行<31>P-MRS。计算了光谱中各峰的信号强度和组织中的pH值。采用相关分析估计死后时间与组织中ATP、PCr和Pi含量以及pH值之间的相关性。回归分析也用于从^<31>P-MRS数据估计死后间隔。在任何杀死方式下，PCr和ATP在死亡后均下降，而Pi随时间增加。死后早期pH值呈线性下降。在死亡前相对缺乏肌肉活动的大鼠的组织中，PCr和ATP含量的减少相对缓慢。当大鼠在剧烈运动、挣扎或抽搐后死亡时，PCr和ATP含量的下降速度加快。在所有的杀菌方式中，pH值的下降速率变化不大。在任何杀死方式下，所有^<31>的P-MRS数据均显示与死后时间有显著相关性。组织内pH值与死后时间有密切关系。最小二乘回归分析成功地估算了^<31>P-MRS数据的死后间隔。虽然数据点有一定程度的分散，但计算出的R平方值很高。我们目前的结果表明，^<31>P-MRS数据可以作为估计死亡时间的手段。特别是在死亡后的早期阶段，pH值通常被认为是估计死亡时间最可靠的方法之一。少