褪黑素对电离辐射诱导小鼠淋巴细胞凋亡的影响  

Effects of melatonin on apoptosis of lymphocytes induced by ionizing radiation in mice

作　　者：张萱[1] 龚守良[1] 王珍琦[1] 吕喆[1] 刘扬[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,吉林长春130021

出　　处：《中国病理生理杂志》2004年第9期1702-1705,共4页Chinese Journal of Pathophysiology

摘　　要：目的探讨褪黑素(MLT)对电离辐射诱导小鼠胸腺细胞和脾细胞凋亡的影响及其机制。方法采用流式细胞术(FCM)和荧光分光光度法分别检测离体和在体小鼠淋巴细胞凋亡小体百分率和DNA裂解率。结果在离体研究中,小鼠胸腺和脾淋巴细胞体外接受(05-60)GyX射线照射前预先加入2mmol/LMLT,细胞凋亡小体百分率和DNA裂解率均显著低于单纯照射组,胸腺和脾淋巴细胞凋亡小体百分率分别为单纯照射组的8625%和8944%,DNA裂解率分别为单纯照射组的8723%和8916%。在体研究中,2GyX射线全身照射前60min腹腔注射MLT,小鼠胸腺和脾淋巴细胞凋亡小体百分率和DNA裂解率显著低于单纯照射组,接近或低于假照水平,MLT剂量在01-25mg/kg范围内均有作用,但无明显剂量依赖性。结论MLT在体内和体外均可减轻电离辐射诱导的小鼠淋巴细胞损伤,且体内比体外作用更明显。AIM: To explore the effect of melatonin (MLT) on the apoptosis of thymocytes and splenocytes in mice induced by ionizing radiation and its mechanism. METHODS: The percentages of apoptotic bodies and the DNA lytic rates of thymocytes and splenocytes in mice in vitro and in vivo were detected with flow cytometry and fluorospectrophotometry, respectively. RESULTS: The apoptosis of mouse thymocytes and splenocytes in vitro increased with significant dose-dependence in 0 5-6 0 Gy X-irradiation. When MLT of 2 mmol·L -1 was added into thymocytes or splenocytes in vitro before irradiation with 0 5-6 0 Gy X-rays, the percentages of apoptotic bodies and the DNA lytic rates all decreased significantly as compared with those in the irradiation group. The percentages of apoptotic bodies in these two kinds of cells were 86 25% and 89 22% of those in the irradiation group, respectively, and the DNA lytic rates were 87 23% and 89 16%, respectively. When MLT was injected into intraperitonium in mice 60 min before whole-body irradiation with 2 Gy X-rays, the percentages of apoptotic bodies and the DNA lytic rates were significantly lower than those in the irradiation group, and near or lower than those in the sham-irradiation group. MLT of 0 1-2 5 mg/kg decreased the lymphocyte apoptosis, but without significant dose-dependence. CONCLUSION: The protective effects of MLT on mouse lymphocytes damaged by irradiation in vivo are obvious than those in vitro. [

关 键 词：褪黑激素 辐射 电离 细胞凋亡 淋巴细胞 

分 类 号：R363[医药卫生—病理学]