TIME-RELATED AND DOSE-RELATED CHANGES IN THE WHITE MATTER OF THE RAT-BRAIN AFTER SINGLE DOSES OF X-RAYS
TIME-RELATED AND DOSE-RELATED CHANGES IN THE WHITE MATTER OF THE RAT-BRAIN AFTER SINGLE DOSES OF X-RAYS
复制标题
DOI：
10.1259/0007-1285-61-731-1043
复制
发表时间：
1988-11-01
影响因子：
2.6
通讯作者：
YEUNG, TK
中科院分区：
文献类型：
--
作者：
CALVO, W;HOPEWELL, JW;YEUNG, TK
单次剂量17.5 ~ 25gy X射线局部照射大鼠脑后，脑白质坏死，潜伏期为bb0 ~ 26周。照射后39周和52周，坏死发生率与剂量有关。在这些时间与50%白质坏死发生率（ED50）相关的剂量为23.45 +-。0.49和20.98 .+-。分别为0.91 Gy。在这两个时期，坏死的发生率较高的是内囊和胼胝体的肠膜。这反映了出现坏死的潜伏期的变化。坏死较早发生在毛层。胼胝体和内包膜出现坏死的潜伏期也呈剂量依赖性。在绒毛坏死发作前的潜伏期，在脉管系统和相关的星形胶质细胞中可以看到许多剂量相关的变化。这些变化，包括血管扩张、血管壁增厚、内皮细胞核增大和血管周围星形胶质细胞肥大，是高度相关的，当它们结合起来时，似乎代表了一个“组织损伤单位”。这种“组织损伤单位”的发生率和严重程度随着照射后时间的延长而明显增加，直至确保坏死。这些与剂量相关的血管/神经胶质改变发生在内皮细胞和血管密度降低之前。早期未见胶质实质细胞数量的变化。
Following the local irradiation of the rat brain with single doses of 17.5-25 Gy of X rays, necrosis of the white matter was seen after a latent interval of > 26 weeks. At 39 weeks and 52 weeks after irradiation the incidence of necrosis was dose-related. The doses associated with a 50% incidence of necrosis in the white matter (ED50) at these times were 23.45 .+-. 0.49 and 20.98 .+-. 0.91 Gy, respectively. At both these times the incidence of necrosis was higher in the fimbria in the capsula interna and the corpus callosum. This reflects a variation in the latency time for the appearance of necrosis. Necrosis occurs earlier in the fimbria. In the corpus callosum and the capsula interna the latency times for the appearance of necrosis were also dose-dependent. In the latent prior to the onset of necrosis of the fimbria, a number of dose-related changes were seen in the vasculature and the associated astroglial cells. These changes, which included blood vessel dilation, blood vessel wall thickening, endothelial cell nuclear enlargement and the hypertrophy of perivascular astrocytes, were highly correlated and when combined appeared to represent a "unit of tissue injury". The incidence and severity of this "unit of tissue injury" apparently increased with time after irradiation until necrosis ensured. These dose-related vascular/glial changes were preceded by a reduction in the endothelial cell and vascular density. No early changes were seen in the number of glial parenchymal cells.