Harrison P J, Heath P R, Eastwood S L, Burnet P W, McDonald B, Pearson R C
Department of Psychiatry, University of Oxford, UK.
Neurosci Lett. 1995 Nov 24;200(3):151-4. doi: 10.1016/0304-3940(95)12102-a.
To help account for the variable quality and quantity of RNA in human brain, we have studied the effect of premortem (agonal state) and postmortem factors on the detection of poly(A)+mRNA and eight mRNAs. For comparison, the influence of the same factors upon gene products encoded by the mRNAs was studied immunocytochemically or by receptor autoradiography. Brain pH declined with increasing age at death and was related to agonal state severity, but was independent of postmortem interval and the histological presence of hypoxic changes. By linear regression, pH was significantly associated with the abundance of several of the RNAs, but not with poly(A)+mRNA, immunoreactivities, or binding site densities. Postmortem interval had a limited influence upon mRNA and protein products. Freezer storage time showed no effect. Parallel rat brain studies showed no relationship between postmortem interval (0-48 h) and amounts of total RNA, poly(A)+RNA, or two individual mRNAs; however, RNA content was reduced by 40% at 96 h after death. pH is superior to clinical assessments of agonal state or mode of death in predicting mRNA preservation. It provides a simple means to improve human brain gene expression studies. pH is stable after death and during freezer storage and can be measured either in cerebrospinal fluid or in homogenised tissue.
为了探究人类大脑中RNA质量和数量的变异性，我们研究了生前（濒死状态）和死后因素对多聚腺苷酸（poly(A)+）mRNA和8种mRNA检测的影响。作为比较，通过免疫细胞化学或受体放射自显影研究了相同因素对mRNA编码的基因产物的影响。脑pH值随死亡时年龄的增加而下降，且与濒死状态的严重程度相关，但与死后间隔时间以及缺氧变化的组织学表现无关。通过线性回归分析，pH值与几种RNA的丰度显著相关，但与多聚腺苷酸（poly(A)+）mRNA、免疫反应性或结合位点密度无关。死后间隔时间对mRNA和蛋白质产物的影响有限。冷冻保存时间未显示出影响。平行的大鼠脑研究表明，死后间隔时间（0 - 48小时）与总RNA、多聚腺苷酸（poly(A)+）RNA或两种单个mRNA的量之间没有关系；然而，死后96小时RNA含量降低了40%。在预测mRNA保存方面，pH值优于对濒死状态或死亡方式的临床评估。它提供了一种改善人类大脑基因表达研究的简单方法。pH值在死后和冷冻保存期间是稳定的，可以在脑脊液或匀浆组织中进行测量。
