雌激素在脑缺血诱导的大鼠齿状回神经再生中的作用(英文)
Effects of Oestrogen on Ischemia-induced Neurogenesis in the Dentate Gyrus of Rats(in English)
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摘要: 为研究雌激素对成年动物局灶性脑缺血诱导成年动物海马齿状回神经元再生的影响，将雄性SD大鼠分为假手术+雌激素组(SE)、假手术+生理盐水替代组(SN)、缺血+雌激素组(ME)和缺血+生理盐水替代组(MN)，右侧大脑中动脉闭塞(MCAO)建立脑缺血模型。在缺血90 min后恢复供血再灌注，分别于再灌注后1 3、12、24和28 h处死老鼠并检测各组大鼠脑梗死体积、细胞凋亡以及脑缺血诱导的成年动物海马齿状回神经元再生的情况。在5个时间点的检测中，ME组脑梗死体积显著小于SE组(P<0.05)；在MCAO大鼠中，海马齿状回区域并未发现有神经元丢失及凋亡的现象。同时，MN组与SN组相比较，损伤侧齿状回新生神经元数目明显增多(P<0.05)，说明这种缺血诱导的神经元再生并不依赖于齿状回区域神经细胞的死亡；ME组与MN组相比较，损伤侧新生神经元数目显著增多(P<005)；SE与SN组相比较，手术侧和对侧的新生神经元数目都显著增加(P<0.05)。结果提示雌激素对局灶性脑缺血后海马齿状回神经元再生具有促进作用，且这种促进作用与海马缺血损伤程度无关。Abstract: To study the effects of oestrogen on ischemiainduced neurogenesis in the hippocampal dentate gyrus, thirty-two adult male rats were randomly divided into four groups：the control surgery group with oestrogen administration (SE), the control surgery group with normal saline administration (SN), the middle cerebral artery occlusion (MCAO) group with oestrogen administration (ME) and the MCAO group with normal saline administration (MN). The MCAO rats were occluded for 90 min by an intraluminal filament and then recirculated. After 1, 3, 12, 24 and 28 h of MCAO, the rats of the four groups were killed to investigate the infarct volume, apoptosis and neurogenesis. The cerebral infarct volume in the ME group was significantly smaller than that of the MN group (P<0.05). No significant cell loss was seen in the dentate gyrus. Cerebral ischemia led to increased neurogenesis, which is independent of cell death in the ipsilateral dentate gyrus (P<0.05). BrdU-positive cells in the ipsilateral dentate gyrus of the ME group were significantly increased when compared with those of the MN group(P<0.05). In the SE group, BrdU-positive cells in both the ipsilateral and contralateral dentate gyrus, were increased when compared with those of the SN group (P<0.05). We concluded that oestrogen plays an important role in neurogenesis, which is independent of ischemia-induced by MCAO in the hippocampal dentate gyrus of rats.
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