大鼠放射性脊髓损伤后神经元数量变化规律  

Regulation of Number of Neurons Following Radiation-induced Spinal Cord Injury in Rats

作　　者：张晶[1,2] 魏丽 孙万良[2] 章金刚[4] 游华[2] 张伟京[2] 

机构地区：[1]解放军总医院,北京100853 [2]军事医学科学院附属医院淋巴瘤/头颈部肿瘤科,北京100071 [3]重庆市人口和计划生育科学技术研究院,重庆400020 [4]军事医学科学院野战输血研究所三室,北京100850

出　　处：《现代生物医学进展》2013年第7期1219-1222,共4页Progress in Modern Biomedicine

基　　金：国家自然科学基金(81001220;30972974);全军医学科研"十二五"课题(CWS11J088);创伤;烧伤与复合伤国家重点实验室开放基金(SKLKF201204);呼吸和肺循环疾病北京市重点实验室开放课题(2011-3);丰台区科技新星计划项目;军事医学科学院附属医院创新科研基金(FC-2012-07);机器人学国家重点实验室开放课题(RLO200810);首都医学发展科研基金(2009-3070)

摘　　要：目的:临床放射治疗中,中枢神经系统是主要的剂量限制器官之一。随着放射治疗学的发展,放射性脊髓损伤的发病率明显增高,其主要病理学变化是血管损伤,伴白质坏死及脱髓鞘。但是对于放射性脊髓损伤后神经元的变化情况未见报道。本文主要阐明大鼠放射性脊髓损伤后180天的时间内,神经元数量的变化情况。方法:将60只Sprague-Dawley(SD)大鼠随机分为未照射组和照射组,照射组采用60Co放射治疗机行30 Gy大鼠颈髓C2-T2单次照射,剂量率为153 cGy/min,源皮距为80 cm,照射时长为1153秒,照射范围为2.0×1.0 cm。未照射组大鼠于照射前灌注取材,照射组大鼠于照射后1、3、7、14、21、30、60、90、120、150、180天进行灌注取材,标本经石蜡包埋,切片后采用尼氏染色法染色,采用Image Pro-Plus(IPP)图像分析软件计量直径大于20μm的神经元数量。结果:正常神经元胞膜完整,胞浆内有清晰蓝染的尼氏体颗粒。大鼠放射性脊髓损伤后,神经元数量在照射后7天即有明显下降。随着时间的延长,神经元数量继续降低,照射后90天达到最低值。照射后180天,神经元数量有所恢复,但无法恢复至正常水平。结论:阐明了大鼠放射性脊髓损伤后神经元数量的变化规律,放射性脊髓损伤后可减少脊髓神经元数量,导致脊髓神经元变性、凋亡、坏死,最终导致脊髓运动功能不可逆性损伤,为临床上放射性脊髓损伤的预防提供理论依据。Objective： The central nervous system is one of the major dose-limiting organs in clinical radiotherapy. With the devel- opment of radiation therapy, the incidence of radiation-induced spinal cord injury is significantly increasing. Vascular dysfunction, white matter necrosis and demyelination are prominent features in spinal cord radiation-induced injury. The aim of this study was to determine the regular of number of neurons following radiation-induced spinal cord injury in rats. Methods： 60 rats were randomly divided into non-irradiation group and irradiation group, the rats of irradiation group received single dose 30 Gy 7 ray beams to a 2.0 cm cervical spine field spanning C2-T2 using ~o teletherapy unit. Dose rate was 153 cGy/min, and rats were 80 cm from the radiation source. Irradi- ation time was 1153 seconds, irradiation range was of 2.0× 1.0 cm. The rats of non-irradiation group were perfused fixation and were made sections before irradiation. The rats of irradiation group were perfused fixation and were made sections post-irradiation1, 3,7,14,21,30,60,90, 120,150,180 days. Sections were performed nissl staining and count the number of neurons of larger than 20 ixm in diameter. Results： The number of neurons was decreased in the early stage following radiation-induced spinal cord injury in rats and reached the lowest point in the 90 days, subsequently recovered slightly in the 180 days. Conclusion： Radiation-induced spinal cord injury in rats can reduce the number of neurons resulting in neurons degeneration, necrosis, apoptosis in rats and eventually lead to motor func- tion irreversible damage in rats spinal cord.

关 键 词：放射性脊髓损伤 神经元数量 Γ射线 照射 

分 类 号：Q95-3[生物学—动物学] R651.2[医药卫生—外科学]