实验性肿瘤压迫大鼠脊髓

EXPERIMENTAL NEOPLASTIC SPINAL CORD COMPRESSION IN RATS

将10~6个 Walker 256癌细胞经皮注射到35只 Wistar 大鼠 T_(13)椎体的前方引起脊髓压迫损害。接种后5～10天出现截瘫和括约肌功能障碍。根据大鼠后肢功能将其分为0(正常)～4级。应用 CT 和 MRI 扫描测量椎旁肿瘤大小。24和6只动物分别作了光镜和电镜观察。发现肿瘤穿透椎骨或椎间孔浸润到硬膜外,受压的脊髓白质的髓鞘间隙增宽及脱髓鞘现象,到晚期髓鞘和轴索崩解。但灰质运动神经元改变较轻。受压段背髓毛细血管扩张,以后塌瘪,内皮细胞间隙增宽,渗透性高,常有红细胞溢出。实验结果表明,机械压迫,脊髓内循环障碍和轴索破坏是造成截瘫的主要原因。

Spine cord compression was induced in 35 Wistar rats by percutaneous inoculationof 10~6 celles of Walker 256 carcinoma anterior to the T13 vertebral body.Paraplegiaand incotinenee occurred after 5～10 days.The animals were graded with respect to hi-ndlimb function from 0(normal)to 4(no movement).The paravertebral tumor volumewas mesured with use of CT and MRI scanning.24 and 6 animals with various extentparalysis were respectively used for light and electron microscopic study.The tumorinvaded the epidural space penetrating the vetebral bone or the intervetebral foramina.The study of the compressed cord segments revealed enlarged intermyelin space and de-myelination in the white matter.In late stage myelins sheaths and axons were brokendown.The motor neurons changed mildly.The capillaries in the compressed cord sogmentswere dilated,then they collapsed.The interepithelia space of them widened.Often,redblood cells were extravasated.It suggests that compression circulatory disturbarce andaxon destruction in the spinal cord play important roles in paraplegia,