不同剂量率X射线辐照对小鼠免疫系统的影响

目的 检测经相同剂量不同剂量率X射线照射的BalB／C小鼠外周血淋巴细胞周期及胸腺和脾脏指数。方法 18只BalB／c小鼠随机分为对照组（controI），低剂量率照射组（20cGy／min）和高剂量率照射组（300cGy／min），每组6只。低剂量组和高剂量组采用剂量率分别为2．0cGy／min和300cGy／min的1GyX射线对小鼠进行全身照射，24h后取血及器官，用流式细胞仪检测外周血淋巴细胞的周期变化，用称量的方法得到胸腺和脾脏指数。结果 高剂量率辐射时，小鼠外周血淋巴细胞的损伤较低剂量时大，而且对雄性鼠的影响大于雌性；同时，胸腺和脾脏指数变化也随着剂量率的增大而减小。结论 低剂量率的照射对小鼠外周血淋巴细胞、胸腺和脾脏的影响较高剂量率辐射小；雌性鼠的辐射耐受能力较雄性强。

Effects of Irradiation with Different Dose Rates of X-ray on Mouse Immune System

Objective To investigate the effects of irradiation with different dose rates of X-ray on mouse immune system. Method Eighteen BalB/C mice were divided into 3 groups randomly: control group,low dose rate irradiated group(20 cGy/min) and high dose irradiated rate group(300 cGy/min).The low and high dose rate irradiated groups were irradiated with 1 Gy of X-ray at 20 cGy/min and 300 cGy/min. Lymphocyte cycle and apoptosis were determined by flow cytometry, and thymus and spleen indices were measured by weight. Result The damages caused to exposure at low dose rate to peripheral blood lymphocytes were less than that at higher dose rate. Meanwhile, thymus and spleen indices declined with the increase of dose rate. The irradiation effects on male-mice were stronger than those on females. Conclusion The lower dose rate can reduce radiation damage to the immune system than the higher dose rate; and female mice are more radiation resistant than males.