全身照射小鼠血清中不同化学形态铜元素含量变化研究

Serum copper in different chemical states in whole body γ-ray irradiated mice

目的采用火焰吸收原子分光光度法（FAAS）检测全身照射小鼠血清中不同化学形态铜元素含量,探究辐照后小鼠血清铜元素含量变化机制及其作为生物剂量计的可行性。方法昆明种雄性小白鼠78只,鼠龄5周,体质量20~22 g,清洁级。按随机数字表法,根据照射剂量0、4.0、6.0、8.0 Gy分为对照组与照射组,再根据照射时间1、4、10、24 h共分为13组,每组6只。照射组1~4亚组给予4.0 Gy剂量照射,照射时间为1.5 min;5~8亚组给予6.0 Gy剂量照射,照射时间为2 min 15 s;9~12亚组给予8.0 Gy剂量照射,照射时间为3 min;对照组不给予照射。从小鼠眼眶取血后分离血清,用乙醇蛋白沉淀法分离血清中不同化学形态铜元素,火焰原子吸收光谱法测量血清铜质量浓度。采用单因素方差分析法对所得数据进行处理。结果不同剂量照射小鼠游离态血清铜质量浓度24 h内变化无统计学意义（P〉0.05）;照射后24 h内小鼠结合态血清铜质量浓度变化有统计学意义（P〈0.05）,其中照射剂量为4.0 Gy、6.0 Gy时变化趋势为先上升后下降,峰值分别位于4 h、10 h处;照射剂量为8.0 Gy时变化趋势为单调上升。照射后24 h小鼠结合态血清铜质量浓度、血清铜总质量浓度与辐照剂量呈良好线性关系,直线方程为Y=0.047 3X＋0.365 4、Y=0.048 6X＋0.530 9（R2=0.972 6、0.982 6）。结论照射小鼠体内血清铜元素含量发生变化,主要体现在血清中参与细胞保护与修复等生理活动的结合态铜元素含量变化;生物体在调控结合态铜元素含量变化来进行细胞保护修复的同时并未产生细胞毒性;照射后24 h小鼠结合态血清铜质量浓度、血清铜总质量浓度具备发展成为新型生物剂量潜力。

Objective To measure the content of serum copper in different chemical forms in whole- body irradiated mice by flame atomic adsorption spectrophotometry, and to study the mechanism of serum copper change in irradiation and the prospect of serum copper as biological dosimeter. Methods Seventy-eight male Kun Ming mice aged 5-week with body weight of 20 - 22 g were randomly divided into control group and irradiated group according to different irradiation dosage of 0, 4.0, 6.0 and 8.0 Gy, the mice in irradiated groups were then divided into 13 sub-group（n = 6） according to different irradiation time of 1, 4, 10, 24 hours. Sub-group 1 - 4 received 4.0 Gy dosage irradiation for 1.5 minutes, sub-group 5 - 8 received 6.0 Gy dosage ir- radiation for 2 minutes and 15 seconds, sub-group 9 - 12 received 8.0 Gy dosage irradiation for 3 minutes, while control group received no irradiation. Serum copper was collected from orbital of mice, treated with ethanol sedimentary method to separate serum copper at different chemical state and atomic absorption was detected with flame spectrometry. One-way analy- sis of variance was used to analyze the difference of serum copper. Results The concentration change of free serum copper in mice receiving less than 24-hour irradiation was no statistical significant（P 〉 0.05）; The concentration change of protein- bind- ing serum copper in mice receiving less than 24-hour irradiation was statistical significant（P 〈 0.05）. The concentration increased at first and then decreased in 4.0 Gy and 6.0 Gy dosage groups, and the maximum value of concentration appeared at 4-hour and 10-hour, respectively. In 8.0 Gy dosage group, the concentration kept increasing during the observation. Dose-response relationship of serum copper in binding state and total serum copper after 24-hour irradiation showed good linearity, and the linear equation was Y = 0.047 3X ＋ 0.365 4, Y = 0.048 6X ＋ 0.530 9（R2 = 0.972 6, 0.982 6）. Conclusion The concentration change of serum copper under irradiation mainly reflect as the content of binding in the physiological activities of cell protec- tion and restoration in serum, and no cytotoxicity is produced during the regulation of serum copper content. The mice binding serum copper after irradiation has the potential to be used as biological dosimeter.