He Qi, Luo Yanmin, Lv Fulin, Xiao Qian, Chao Fenglei, Qiu Xuan, Zhang Lei, Gao Yuan, Xiu Yun, Huang Chunxia, Tang Yong
Department of Histology and Embryology, Chongqing Medical University, Chongqing, P. R. China.
Laboratory of Stem Cell and Tissue Engineering, Chongqing Medical University, Chongqing, P. R. China.
J Comp Neurol. 2018 Apr 1;526(5):790-802. doi: 10.1002/cne.24366. Epub 2017 Dec 17.
The effects of estrogen replacement therapy (ORT) on white matter and the myelin sheath ultrastructure in the white matter of middle-aged ovariectomized (OVX) rats were investigated in this study. Middle-aged rats were ovariectomized and divided into a placebo replacement (OVX + O) group and an estrogen replacement (OVX + E) group. Then, the Morris water maze, electron microscope techniques, and stereological methods were used to investigate the effects of ORT on spatial learning capacity, white matter volume and the myelin sheath ultrastructure in the white matter. We found that the spatial learning capacity of the OVX + E rats was significantly improved compared with that of the OVX + O rats. When compared with that of OVX + O rats, the total volume of the myelin sheaths in the white matter of the OVX + E rats was significantly increased by 27%, and the difference between the outer perimeter and inner perimeter of the myelin sheaths of the white matter in the OVX + E rats increased significantly by 12.6%. The myelinated fibers with mean diameters of 1.2-1.4 μm were significantly longer (46.1%) in the OVX + E rats; the difference between the mean diameter of myelinated fibers and the mean diameter of axons (0-0.4 μm) was significantly increased by 21.6% in the OVX + E rats. These results suggested that ORT had positive protective effects on the spatial learning ability and on the myelin sheath ultrastructure in the white matter of middle-aged OVX rats.
本研究探讨了雌激素替代疗法（ORT）对中年去卵巢（OVX）大鼠白质及白质髓鞘超微结构的影响。将中年大鼠去卵巢后分为安慰剂替代（OVX + O）组和雌激素替代（OVX + E）组。然后，采用莫里斯水迷宫、电子显微镜技术和体视学方法，研究ORT对空间学习能力、白质体积及白质髓鞘超微结构的影响。我们发现，与OVX + O组大鼠相比，OVX + E组大鼠的空间学习能力显著提高。与OVX + O组大鼠相比，OVX + E组大鼠白质中髓鞘的总体积显著增加了27%，且OVX + E组大鼠白质髓鞘的外周与内周之差显著增加了12.6%。OVX + E组大鼠中平均直径为1.2 - 1.4μm的有髓纤维显著更长（46.1%）；OVX + E组大鼠中有髓纤维平均直径与轴突平均直径（0 - 0.4μm）之差显著增加了21.6%。这些结果表明，ORT对中年OVX大鼠的空间学习能力及白质髓鞘超微结构具有积极的保护作用。
