小白鼠死后脾组织RNA降解程度与死亡时间关系的研究

The Relationship between Postmortem Interval and RNA Degradation in the Spleen of Mice

目的探讨小白鼠死后脾组织GAPDH mRNA和β-actin mRNA降解情况与死亡时间(PMI)的关系。方法 48只NIH小白鼠安乐死处死,分别置于10℃和25℃温控系统内,利用两步法RT-PCR技术和核酸蛋白测定仪定量cDNA方法检测小白鼠脾GAPDH mRNA和β-actin mRNA在死后即刻至72h降解情况。结果在10℃温控系统内的小白鼠死后即刻至72h脾组织均可检测到GAPDH mRNA和β-actin mRNA,且其扩增产物呈规律性下降趋势。25℃温控系统内的小白鼠死后即刻至48h脾组织均可检测到GAPDH mRNA和β-actin mRNA,且其扩增产物呈规律性下降趋势。结论小白鼠死亡后脾GAPDH mRNA和β-actin mRNA降解与PMI负相关,可为PMI推断提供一种新的观测指标。

Objective To explore the relationship between postmortem interval （PMI） and degradation of glyceraldehydes 3-phosphate dehydrogenase （GAPDH） mRNA and β-actin mRNA in the spleen of mice.Methods 48 NIH mice were sacrificed by cervical dislocation and then kept in two different temperature-controlling systems （10℃ and 25℃）.GAPDH mRNA and β-actin mRNA in the spleen were detected by two-step fluorimetric reverse transcriptase polymerase chain reaction （RT-PCR） and nucleic acid protein cryoscope cDNA quantitative methods from 0 to 72 h postmortem.Results The amplification product of GAPDH mRNA and β-actin mRNA could be detected in the spleen when the killed animals were kept in a 10℃ temperature-controlling system.There was a tendency of decrease at 72 h postmortem.When kept at 25℃, GAPDH and β-actin mRNA could also be detected, with a tendency of decrease in the RNA level over time.Conclusion Degradation of GAPDH mRNA and β-actin mRNA in the spleen was negatively correlated with the postmortem interval.This correlation may provide a new index for the estimation of PMI.