循环内皮细胞与放射性脑损伤相关性实验研究

目的 探讨循环内皮细胞(circulating endothelial cells,CECs)与放射性脑损伤相关性。方法 108只SD大鼠信封法随机分成对照组、实验组(10Gy组、30Gy组),分别于照射后1周、1月和3月每组随机抽取9只进行Morris水迷宫行为测试,心脏取血计数CECs,取脑观察海马形态和结构。结果 神经行为改变:照射1和3个月后平台潜伏期延长、穿越平台象限时间及次数明显减少。海马齿状回形态改变:照射1和3个月后实验组神经胶质酸性蛋白(glial fibrillary acidic protein,GFAP)阳性细胞数量明显高于对照组,30Gy组高于10Gy组;照射1和3个月后超微结构变化为毛细血管内皮细胞变薄、内皮细胞吞饮小泡明显增多、内皮细胞间紧密连接破坏,毛细血管基膜外星形胶质细胞足板水肿,毛细血管周围星形胶质细胞水肿,30Gy组重于10Gy组。CECs变化:照射1周和1月后脱落CECs数量较对照组明显增多,与平台潜伏期正相关(r_10Gy=0.97,r_30Gy=0.95),与GFAP阳性细胞数量正相关(r_10Gy=0.94,r_30Gy=0.96)。结论 CECs数量改变与放射性脑损伤正相关,脑损伤随照射剂量增加、时间延长而加重。

Correlation between circulating endothelial cells and radiation-induced brain injury

Objective To investigate the correlation between circulating endothelial cells (CECs) and radiation-induced brain injury. Methods One hundred and eight SD rats were randomly divided into control group, single-dose 10Gy ⁶⁰Co irradiation group and single-dose 30Gy group. The neurobehavioral changes were observed by Morris water labyrinth at 1 week, 1 month and 3 months after irradiation. The CECs in right ventricular blood were counted after Morrie water test. Hippocamp ultramicrostructure and GFAP positive cell were detected after perfusion of encephalon. Results Neuobehavior change: at 1 month and 3 months after irradiation the swim latency was significantly prolonged (30Gy group>10Gy group>control group, P<0.05).The time of swim in the platform quadrant and the times of swim through the plateau region were significantly reduced (control group>10Gy group>30Gy group, P<0.05).Hippocamp dentate gyrus change: at 1 month and 3 months after irradiation the numbers of GFAP were significantly increased (30Gy group>10Gy group>control group, P<0.05).Vascular endothelium became thinner, pinocytotic vacuole of endothelium increased and the tight junctions that connected capillary endothelial cells were ruptured. The glial perivascular feet and astrocytes surrounding the basement membrance were swollen. At 1 week and 1 months after irradiation the CECs numbers were obviously increased (30Gy group>10Gy group>control group, P<0.05). Good correlations between the numbers of CECs and the swim lantency (r_10Gy=0.97, P=0.034; r_30Gy=0.95, P=0.013), and the numbers of GFAP positive cells(r_10Gy=0.94,P=0.037; r_30Gy=0.96,P=0.027) were demonstrated.Conclusion The changes of the CECs numbers are definitely correlated to radiation-induced brain injury, which is more with irradiation dose and duration.