大鼠死后脑组织FTIR光谱变化与死亡时间的关系  

The Correlation between Postmortem Interval and Fourier Transform Infrared Spectra in Rat's Brain

作　　者：柯咏[1] 王世伟[2] 鲁庆阳[1] 黄平[1] 邢博[1] 王振原[1] 

机构地区：[1]西安交通大学医学院法医学系,陕西西安710061 [2]西安市公安局新城分局,陕西西安710043

出　　处：《光谱学与光谱分析》2008年第11期2545-2549,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(30471935)资助

摘　　要：应用傅里叶变换红外(FTIR)光谱技术分析大鼠死后脑组织随死亡时间推移的化学变化过程,为死亡时间推断的研究提供新的途径与数据。大鼠断颈处死后置于室温(20±2)℃环境下,在不同时间点提取大鼠脑皮质,运用FTIR光谱仪检测不同化学基团的变化。随着死亡时间的推移,大鼠脑组织FTIR光谱的主要吸收峰峰位没有明显变化,而其峰高有明显差异:(1)与核酸有关的谱带的相对峰强呈明显下降趋势;(2)酰胺Ⅱ和Ⅰ的峰强比呈上升趋势;1 338,1 313 cm-1,1 398 cm-1的峰强比呈下降趋势。(3)1 456和1 398cm-1谱带的峰强各自呈下降和上升趋势。(4)2 852,2 871,2 923,2 958 cm-1的峰强相对于1 647 cm-1而言,呈现上升趋势。In the present study,FTIR spectroscopy was applied to observe the process of postmortem degradation in rat＇s brain and a lot of useful data for the estimation of postmortem interval（PMI） were provided.Sprague-Dawley male rats（weight 240±10 g） were chosen and sacrificed by cervical dislocation.The bodies were kept in a controlled environmental chamber set at （20±2） ℃,and their brain cortex as the measuring sample which was extracted at 0,12,24,48,72,96,120,144 and 168 h from the 8 rats.The tissues were freeze dried in a vacuum at-50 ℃ overnight in order to dehydrate them.About 2 mg freeze dried tissues were mixed with 200 mg KBr and then ground in an agate mortar for 5 min.The mixture then was pressed into a pellet with a thickness of 0.4 mm and a diameter of 12 mm.The FTIR spectra were quantitatively recorded at room temperature in the range 4 000-400 cm-1 on a Shimadzu 8400S spectrometer（Shimadzu,Japan）.IR solution 1.10 software（Shimadzu,Japan） was used for the analysis of the FTIR spectra and for recording the data from the spectra.With the PMI increasing,the peak position of main absorbance bands in the FTIR spectra showed no significant difference,but there was a dramatic variance in the intensity：（1） The relative intensity at 1 080 and 1 238 cm-1（I1 080/I1 398 and I1 238/I1 398） related with nucleic acid tended to decrease obviously.（2） The intensity ratio at amide Ⅱ and Ⅰ（I1 541/I1 647） increased with the PMI increasing.The intensity at 1 338 and 1 313 cm-1 varied slightly,but their intensity ratio to 1 398 cm-1 decreased.（3） The intensity at 1 456 and 1 398 cm1 showed a trend of decreasing and increasing respectively.（4） Compared with the intensity at 2 871 cm-1,the intensity at 2 852,2 871,2 923 and 2 958 cm-1 tended to increase,but the increasing tendency at 2 871 cm-1 was slight.It is concluded that FTIR spectroscopy is going to be an effective method for estimating the PMI in medicolegal practice and the brain tissue may be a suitable marker as

关 键 词：FTIR 死亡时间 脑组织 化学基团 

分 类 号：O657.3[理学—分析化学]