短暂脑缺血后成年和老年大鼠大脑髓鞘相关蛋白基因表达变化

目的探讨短暂脑缺血后成年和老年大鼠大脑髓鞘相关蛋白基因表达变化及其意义。方法以线栓法制作成年和老年SD大鼠短暂脑缺血模型（阻塞60min再灌注1d、7d和14d）；采用5末端标记地高辛的寡核苷酸探针荧光原位核酸分子杂交检测短暂脑缺血大鼠大脑梗死中心区、梗死周边区和梗死对侧区PLP mRNA和MyT1 mRNA照射后表达变化，并计数阳性细胞数量。结果（1）短暂脑缺血后成年和老年大鼠大脑皮质梗死中心区PLP mRNA和MyT1 mRNA阳性细胞数明显减少，两组之间比较无显著差异。（2）短暂脑缺血后早期成年和老年大鼠梗死周边区PLP mRNA和MyT1 mRNA阳性细胞数无明显变化，之后（7d和14d）逐渐增加，成年大鼠PLP mRNA和MyT1 mRNA阳性细胞数增加更明显。结论成年大鼠短暂脑缺血后急性期梗死周边区髓鞘相关蛋白基因表达强于老年大鼠，提示年龄是影响少突胶质前体细胞参与脑缺血后损伤修复的因素之一。

The altered expression of myelin associated proteins'genes in adult and aged rats after transient cerebral ischemia

Objective To explore the expression and meaning of myelin associated proteins＇ genes in adult and aged rats after transient cerebral ischemia. Methods Transient cerebral ischemia model was established in male adult SD rats by occluding the right middle artery with 4-0 nylon thread （blood flow blocked for 60 minutes and then reperfused for 1,7 and 14 days）. The early phase expression of the genes of PLP and MyT1 was examined by fluorescent in situ hybridization with the dig-labeled oligonucleotides and count of the positive cells was taken. Results The number of PLP- and MyT1- positive cells within the ischemic core of adult and aged rats decreased significantly after transient cerebral ischemia and had no obvious difference between young and aged rats. There was no obvious change with the number of PLP- and MyT1 - positive cells within ischemic penumbra immediately after reperfusion, that however increased gradually at 7th day and 14th day after transient cerebral ischemia. PLP- and MyT1 - positive cells in adult rats increased more than that in aged rats. Conclusions The early phase expression of PLP mRNA and MyT1 mRNA in the peri-infarct area in the adult rat brain is more than that in aged rats, suggesting that age influence oligodendrocyte precursor cells participating the repairing of the post-ischemic brain injury.