高血压大鼠第四脑室外侧隐窝室管膜细胞的形态学变化

Morphological observation on ependymal cells in lateral fourth ventricle in hypertensive rat

目的：观察NO缺乏型高血压大鼠第四脑室外侧隐窝室管膜细胞的形态学变化、分泌情况及巢蛋白表达变化。方法：雄性Wistar大鼠，以左旋硝基精氨酸（L-NNA）15mg／d腹腔注射，成功制备高血压动物模型。随机选择对照组、用药2周组、用药4周组，常规灌注取脑，取材后经处理，左、右两侧分别进行巢蛋白免疫显色和透射电镜观察。结果：巢蛋白免疫组织化学显色显示，随着血压的升高，呈现先加深后变浅的趋势。透射电镜下对照组室管膜细胞排列整齐，边界清楚，纤毛和微绒毛丰富。在用药2周组，室管膜细胞体积大小不等，形态各异，边界不清，胞核皱缩，染色质粗大，细胞游离面纤毛较少，可见向细胞顶部突出的“淤泥样”分泌物。用药4周组，室管膜细胞分泌活动更加旺盛。结论：透射电镜下观察到，第四脑室外侧隐窝室管膜面上特殊“淤泥样”分泌物的分泌过程，而且随血压升高，分泌功能更加旺盛，说明该处细胞对高血压刺激敏感。

Objective： To observe the morphological changes of ependymal cells in the lateral recess of the fourth ventricle （LR4V） of the NO deficient hypertensive rats at different time, as well as the secretion of ependymal cells, and to study the Nestin expression in ependymal cells. Methods： 30 healthy male Wistar rats were randomly divided into three groups： A control group injected with normal saline; Medication group： medication 2-week group; Medication 4-weeks group. Preparation for the animal model of NO deficient hy- pertensive rats were treated with nitric oxide synthase inhibitor-L-nitro-L-arginine （L-NNA） with 15 rng/d by intraperitoneal injec- tion, and were successfully prepared animal models of hypertension. Three rats were randomly selected in each group for conventional cardiac perfusion and fixation were done, then the rat brain was taken out and observed under a transmission electron microscope （TEM）, and the paraffin sections were stained with nestin immunohistochemical staining. Results： With an increase in blood pres- sure, the staining of nestin-positive ependymal cells of LR4V showed a trend from deep to shallow. The results of TEM observation： in the control group, the ependymal cells were arranged regularly, with rich cilia and microvilli, and the borders were clear. In the 2- week medication group, the ependymal cells were various in size and shape, and the border was unclear. The nuclei were shrinkage with coarse chromatin. There were less cilia on free surface of ependymal cells, ＂mud-like＂ discharge can be seen at the top of cells. In the 4-week group, secretory activities of ependymal cells were more vigorous. Conclusion： Under TEM, it is observed that the process of discharge special ＂mucHike＂ secretion in ependymal cells of LR4V, and with increasing blood pressure, secretory activities of ependymal cells are more vigorous, indicating that the ependymal cells are sensitive to hypertension.