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电离辐射可以引起机体免疫系统损伤,0.5 Gy以上的照射剂量就能引起免疫系统抑制,半数致死剂量以上的照射则可以导致免疫系统的全面抑制。胸腺是免疫系统中重要的中枢免疫器官之一,是淋巴细胞分化发育成熟的重要场所,对周围免疫器官的发育和正常功能的发挥有重要作用[1]。胸腺是对电离辐射十分敏感的免疫器官,因此,在辐射防护中增强对免疫系统,特别是胸腺的辐射防护显得非常重要。由于人体中水分约占体重的70%,因此,电离辐射产生的大量活性氧可造成正常结构的破坏,进而引起组织器官的损伤[2]。富氢水中氢的含量非常高,氢气穿透力强,能够非常容易地进入细胞内,选择性地中和羟基自由基等活性氧成分,将活性氧还原成水并排出体外,因此具有强大的抗氧化能力。本研究旨在观察富氢水对电离辐射引起的胸腺细胞损伤的防护作用,为进一步开发富氢水作为安全、无不良反应的辐射防护剂及其他防护剂的溶解载体提供依据。
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如图 1所示,6 Gy照射的小鼠胸腺细胞在照射后4、7、15 d活性氧水平都明显升高,而且随着时间的增加活性氧水平有下降的趋势。与单独6 Gy照射的小鼠相比,给予富氢水的受照小鼠的胸腺细胞的活性氧水平明显降低,但是在照射后4和15 d仍然比对照组小鼠高,只有照射后7 d活性氧水平低于对照组,提示富氢水能够有效降低辐照引起的细胞内活性氧水平升高。
图 1 富氢水对受照射小鼠胸腺细胞内活性氧水平的影响图中,A:富氢水对受照后4、7、15 d小鼠胸腺细胞活性氧的影响;B:照射后4 d代表性的活性氧变化流式示意图。其中,B图中纵坐标count代表细胞数目,横坐标FL1-A代表检测活性氧水平的发射光接收通道。与对照组比较,a:t=5.607,P<0.05;c:t=16.080,P<0.05;e:t=8.946,P<0.05;与6 Gy照射组比较,b:t=2.142,P<0.05;d:t=20.580,P<0.05;f:t=4.622,P<0.05。
Figure 1. Effects of hydrogen-rich water on reactive oxygen species in thymus of irradiated mice
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如图 2所示,6 Gy照射小鼠胸腺细胞在照射后4、7、15 d早期凋亡细胞(AnnexinⅤ阳性、PI阴性)和晚期凋亡细胞(AnnexinⅤ阳性、PI阳性)百分比增加;与单独6 Gy照射的小鼠相比,给予富氢水的受照小鼠的胸腺细胞中早期凋亡和晚期凋亡细胞的百分比下降,早期凋亡细胞百分比在照射后4和15 d仍然比对照组小鼠高,只有在照射后7 d细胞凋亡水平低于对照组,提示富氢水能够减轻辐照引起的胸腺细胞凋亡。
图 2 富氢水对受照小鼠胸腺细胞凋亡的影响图中,A:富氢水对照射后4、7、15 d小鼠胸腺细胞早期凋亡和晚期凋亡的影响;B:照射后15 d代表性的细胞凋亡变化流式示意图。其中,PI:碘化丙啶。与对照组比较,a:t=9.454,P<0.05;c:t=3.363,P<0.05;e:t=4.105,P<0.05;g:t=44.75,P<0.05;i:t=8.146,P<0.05;与6 Gy照射组比较,b:t=6.588,P<0.05;d:t=5.068,P<0.05;f:t=4.114,P<0.05;h:t=9.677,P<0.05;j:t=4.855,P<0.05。
Figure 2. Effects of hydrogen-rich water on apoptosis in thymus of irradiated mice
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如表 1所示,6 Gy照射小鼠胸腺细胞在照射后4、7、15 d代表DNA损伤的γ-H2AX平均荧光强度增加;与单独6 Gy照射的小鼠相比,给予富氢水的受照小鼠的胸腺细胞γ-H2AX平均荧光强度下降,照射后4和7 d仍然比对照组小鼠高,只有在照射后15 d γ-H2AX平均荧光强度接近于对照组,提示富氢水能够降低辐照引起的胸腺细胞DNA损伤。
组别 照射后时间 4 d 7 d 15 d 对照组 10 093±286 10 562±554 12 780±197 6 Gy照射组 15 574±1615a 14 748±810c 15 495±1286e 6 Gy照射+富氢水组 13 876±1743b 12 836±1246d 12 437±805f 注:表中,γ-H2AX:磷酸化组蛋白H2AX。与对照组比较,a:t=7.472,P<0.05;c:t=9.059,P<0.05;e:t=4.666,P<0.05;与6 Gy照射组比较,b:t=1.226,P>0.05;d:t=2.876,P<0.05;f:t=4.507,P<0.05。 表 1 富氢水对受照小鼠胸腺细胞γ-H2AX平均荧光强度的影响(
)$ \bar x \pm {s_{\bar x}}$ Table 1. Effects of hydrogen-rich water on DNA damage in thymus of irradiated mice(mean fluorescence intensity of γ-H2AX)(
)$ \bar x \pm {s_{\bar x}}$
富氢水对电离辐射引起胸腺细胞损伤的影响
Effects of hydrogen-rich water on radiation-induced thymus injury
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摘要:
目的 探讨富氢水对6 Gy照射小鼠胸腺细胞内活性氧水平、细胞凋亡及DNA损伤程度的影响。 方法 实验分为对照组、6 Gy照射组、6 Gy照射+富氢水组;对照组和6 Gy照射组小鼠照射前10 min灌胃正常饮用水0.5 ml,6 Gy照射+富氢水组小鼠灌富氢水0.5 ml,照射后连续灌胃,给予小鼠正常饮用水和富氢水7 d,于照射后4、7、15 d处死小鼠获取胸腺细胞。采用流式细胞术检测胸腺细胞内活性氧水平、凋亡细胞比例及磷酸化组蛋白H2AX(γ-H2AX)平均荧光强度。 结果 与对照组的小鼠比较,6 Gy照射组小鼠在照射后4、7、15 d胸腺细胞中的活性氧水平升高,早期凋亡细胞[AnnexinⅤ阳性、碘化丙啶(PI)阴性]和晚期凋亡细胞(AnnexinⅤ阳性、PI阳性)的细胞比例明显增加,γ-H2AX平均荧光强度增加。与6 Gy照射组小鼠相比,6 Gy照射+富氢水组小鼠的胸腺细胞中活性氧水平下降,早期凋亡和晚期凋亡的细胞比例降低,细胞内γ-H2AX平均荧光强度则是下降的,差异均具有统计学意义。 结论 富氢水可以有效减轻电离辐射引起的胸腺细胞损伤,为富氢水作为辐射损伤防护剂提供了实验依据。 Abstract:Objective The apoptosis and DNA damage of thymus cells in mice with total body irradiation of 6 Gy were investigated to determine the effect of hydrogen-rich water on reactive oxygen species(ROS). Methods A total of 15 mice were divided into three groups, namely, un-irradiated control group, 6 Gy irradiation group, and 6 Gy+hydrogen-rich water group. Up to 0.5 ml of hydrogen-rich water was administered to the mice in 6 Gy+hydrogen-rich water group 10 min before irradiation, which was provided once a day within 7 days after irradiation, and the other two groups were administered water instead. Thymus cells were collected at 4, 7, and 15 days after irradiation. Levels of ROS, apoptosis, and mean fluorescence intensity(MFI) of phosphorylated histone H2AX(γ-H2AX) were detected by flow cytometry. Results ROS levels, early(Annexin V-positive and propidium iodide(PI)-negative) and late apoptotic(Annexin V-positive and PI-positive) cells, and MFI of γ-H2AX increased in the thymus of mice irradiated with 6 Gy compared with those in the un-irradiated control group. By contrast, the levels of ROS, apoptotic cells, and MFI of γ-H2AX significantly declined in the thymus of mice administered with 6 Gy + hydrogen-rich water compared with those in the irradiated mice. Conclusion Hydrogen-rich water exerted a promising protective effect on radiation-induced thymus injury. Therefore, hydrogen-rich water is a potential radioprotective agent. -
Key words:
- Radiation, ionizing /
- Reactive oxygen species /
- Apoptosis /
- DNA damage /
- Hydrogen-rich water /
- Thymus cells
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图 1 富氢水对受照射小鼠胸腺细胞内活性氧水平的影响图中,A:富氢水对受照后4、7、15 d小鼠胸腺细胞活性氧的影响;B:照射后4 d代表性的活性氧变化流式示意图。其中,B图中纵坐标count代表细胞数目,横坐标FL1-A代表检测活性氧水平的发射光接收通道。与对照组比较,a:t=5.607,P<0.05;c:t=16.080,P<0.05;e:t=8.946,P<0.05;与6 Gy照射组比较,b:t=2.142,P<0.05;d:t=20.580,P<0.05;f:t=4.622,P<0.05。
Figure 1. Effects of hydrogen-rich water on reactive oxygen species in thymus of irradiated mice
图 2 富氢水对受照小鼠胸腺细胞凋亡的影响图中,A:富氢水对照射后4、7、15 d小鼠胸腺细胞早期凋亡和晚期凋亡的影响;B:照射后15 d代表性的细胞凋亡变化流式示意图。其中,PI:碘化丙啶。与对照组比较,a:t=9.454,P<0.05;c:t=3.363,P<0.05;e:t=4.105,P<0.05;g:t=44.75,P<0.05;i:t=8.146,P<0.05;与6 Gy照射组比较,b:t=6.588,P<0.05;d:t=5.068,P<0.05;f:t=4.114,P<0.05;h:t=9.677,P<0.05;j:t=4.855,P<0.05。
Figure 2. Effects of hydrogen-rich water on apoptosis in thymus of irradiated mice
表 1 富氢水对受照小鼠胸腺细胞γ-H2AX平均荧光强度的影响(
)$ \bar x \pm {s_{\bar x}}$ Table 1. Effects of hydrogen-rich water on DNA damage in thymus of irradiated mice(mean fluorescence intensity of γ-H2AX)(
)$ \bar x \pm {s_{\bar x}}$ 组别 照射后时间 4 d 7 d 15 d 对照组 10 093±286 10 562±554 12 780±197 6 Gy照射组 15 574±1615a 14 748±810c 15 495±1286e 6 Gy照射+富氢水组 13 876±1743b 12 836±1246d 12 437±805f 注:表中,γ-H2AX:磷酸化组蛋白H2AX。与对照组比较,a:t=7.472,P<0.05;c:t=9.059,P<0.05;e:t=4.666,P<0.05;与6 Gy照射组比较,b:t=1.226,P>0.05;d:t=2.876,P<0.05;f:t=4.507,P<0.05。 -
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