Bruni J E, Clattenburg R E, Paterson J A
Scan Electron Microsc. 1983(Pt 2):649-61.
The response of ependyma to injury was investigated in rats following placement of bilateral lesions in the floor of the fourth ventricle. Animals were sacrificed from 2-60 days post-operatively and the brains were prepared in the conventional manner for comparative LM, SEM and TEM examination. For LM radioautography, randomly selected lesioned rats received either a single i.p. injection (5 muCi/g BW) or multiple injections (2 muCi/g) of 3H-thymidine prior to sacrifice. Focal disruption of the lining resulted in significant qualitative and quantitative changes in the ependyma at the wound margins. Labelling of normally quiescent ependymal cells occurred from day 2-6 post-operatively, however, the level of turnover was relatively low. Labelling was maximum on day 2 and was greater at the medial than lateral margin of the wound. During the first postoperative week, a gradual increase was observed in the number of ependymal cells per unit length at the margins of the wound concomitant with an abrupt reduction in wound diameter. This was consistent with the assumption that newly formed cells were added to the ependymal sheet at the leading edges of the wound. From 14-60 days after injury, further repair resulted from asymmetrical spreading and thinning of the ependymal sheet in the absence of mitotic activity. Quantitatively, this was reflected in a reduction in cell number at the leading edges of the wound that was most pronounced at the lateral margin. At day 60 neither epithelialization nor wound closure was complete and the normal architecture of the lining had not been fully restored. These results suggest that ependyma in the fourth ventricle of the postnatal rat undergoes a process of only limited repair following injury.
在大鼠第四脑室底部双侧损伤后，对室管膜对损伤的反应进行了研究。术后2至60天处死动物，按常规方法制备大脑，用于比较光镜、扫描电镜和透射电镜检查。对于光镜放射自显影，在处死前，随机选择的损伤大鼠接受单次腹腔注射（5μCi/g体重）或多次注射（2μCi/g）的3H-胸腺嘧啶核苷。衬里的局灶性破坏导致伤口边缘室管膜出现显著的定性和定量变化。术后第2至6天，正常静止的室管膜细胞出现标记，但更新水平相对较低。标记在第2天达到最大值，且伤口内侧的标记大于外侧。术后第一周，伤口边缘单位长度的室管膜细胞数量逐渐增加，同时伤口直径突然减小。这与新形成的细胞在伤口前缘添加到室管膜层的假设一致。损伤后14至60天，在无有丝分裂活性的情况下，室管膜层不对称扩展和变薄导致进一步修复。从数量上看，这表现为伤口前缘细胞数量减少，在外侧边缘最为明显。在第60天，上皮化和伤口闭合均未完成，衬里的正常结构也未完全恢复。这些结果表明，新生大鼠第四脑室的室管膜在损伤后仅经历有限的修复过程。
