褪黑素对小鼠脾淋巴细胞电离辐射损伤的防护作用  

PROTECTIVE EFFECT OF MELATONIN ON RADIATION DAMAGE OF SPLENOCYTES IN MICE

作　　者：张萱[1] 龚守良[1] 张铭[1] 刘树铮[1] 

机构地区：[1]吉林大学公共卫生学院卫生部放射生物学重点实验室,长春130021

出　　处：《辐射防护》2005年第1期31-35,共5页Radiation Protection

摘　　要：本文旨在探讨体内补充褪黑素 (melatonin ,MLT)对电离辐射所致小鼠脾淋巴细胞损伤的影响及其机制。实验采用昆明小鼠 ,连续 1周每天腹腔注射 0 .1mg/kg(体重 )的MLT ,第 8天给予 1～ 4Gy全身照射 ,2 4h后检测脾淋巴细胞数量的变化。另外 ,小鼠腹腔单次注射 0～ 2 .5mg/kg(体重 )的MLT ,60min后给予 2GyX射线全身照射 ,1 2h后检测脾淋巴细胞凋亡及细胞周期时相 (用流式细胞术 )和DNA裂解率 (用荧光分光光度法 )的变化。结果发现 :小鼠连续 1周腹腔注射MLT ,1 .0～ 4.0Gy照射后 2 4h ,脾淋巴细胞数呈剂量依赖性降低 (p <0 .0 1 ) ;而受照前连续 1周注射MLT( 0 .1mg·kg- 1·d- 1) ,预先给予MLT组脾淋巴细胞数比预先不给予MLT组显著增高 (p <0 .0 5 )。 2GyX射线全身照射后 1 2h ,细胞凋亡小体百分率和DNA裂解率与对照组相比显著升高 (p <0 .0 1 ) ,G0 /G1期和G2 +M期细胞百分数增高 (p <0 0 5 ) ,S期细胞百分数降低 (p <0 .0 1 ) ,细胞发生G1和G2 期阻滞 ;而照射前单次注射MLT ,其凋亡小体百分率和DNA裂解率均显著降低 (p<0 .0 5或p <0 .0 1 ) ,G1期阻滞缓解 ,G2 期阻滞加剧。以上结果表明照射前预先补充MLT可减轻电离辐射所致小鼠脾淋巴细胞损伤 。This paper is to explore the effect of melatonin (MLT) on the damage of mouse splenocytes induced by whole-body irradiation (WBI) and its mechanism.MLT was administered to Kunming mice by peritoneal injection 60 min before WBI with 1.0～4.0 Gy X-rays. For consecutive administration of MLT, changes in splenocyte number were observed 24 h after WBI; for single administration of MLT,apoptotic body percentage (ABP) and cell percentages of cell cycle phases in splenocytes were determined with flow cytometry, and DNA fragmentation rate (DFR) was assayed by fluorescence spectrophotometry.The number of splenocytes increased significantly after daily consecutive administration of MLT for 1 week,in 0.1 mg·kg -1(BW)group (p<0.01). The number of splenocytes 24 h after irradiation with 1～4 Gy decreased in a dose-dependent manner (p<0.01). The number of splenocytes increased significantly with daily consecutive administration of MLT (0.1 mg·kg -1·d -1) for 1 week before WBI (p<0.05). ABP and DFR of splenocytes increased significantly 12 h after WBI with 2 Gy (p<0.01), and the percentages of G 0/G 1 and G 2+M phase splenocytes increased significantly (p<0.05), indicating G 1 and G 2 arrests. When MLT was administered once before irradiation, ABP and DLR of splenocytes decreased significantly (p<0.05 or p<0.01), G 1 arrest was attenuated while G 2 arrest became more serious.The administration of MLT to mice before WBI has protective effect on immunity as evidenced by decreased damage of splenocytes after WBI.

关 键 词：脾淋巴细胞 小鼠 褪黑素 腹腔注射 损伤 电离辐射 照射 体重 百分率 数量 

分 类 号：R392[医药卫生—免疫学]