微波预先辐照致γ射线对小鼠骨髓基质细胞毒性作用的改变

Pre-exposure with Microwave Alters the Effects of γ-rays on Mouse Bone Marrow Stromal Cells

[目的]探讨微波预先辐照对γ射线致骨髓基质细胞凋亡、线粒体膜电位、胞内游离Ca2+浓度和Ca2+-Mg2+-ATP酶活性改变的影响。[方法]将原代培养的骨髓基质细胞随机分为正常对照组、单纯微波组、单纯γ射线组和联合组。12μW/cm2微波对单纯微波组和联合组连续辐照7d,每天1h,第8天对单纯γ射线组和联合组进行5Gy的γ射线照射。用钙离子依赖性磷脂结合蛋白-异硫氰酸荧光素及碘化丙啶(AnnexinV-FITC及PI)双标记法检测细胞凋亡,流式细胞仪检测线粒体膜电位和胞内游离Ca2+浓度,试剂盒检测Ca2+-Mg2+-ATP酶活性。[结果]与正常对照组相比,各处理组细胞的凋亡率和线粒体膜电位未见明显改变。γ射线照射后24h,单纯微波组、联合组和单纯γ射线组细胞内游离Ca2+浓度明显升高(P<0.05),Ca2+-Mg2+-ATP酶活性明显降低(P<0.05)。与单纯γ射线组相比,联合组细胞内游离Ca2+浓度明显降低(P<0.05),Ca2+-Mg2+-ATP酶活性明显升高(P<0.05)。[结论]本实验条件下,900MHz,12μW/cm2的微波辐射和5Gyγ射线均不能引起细胞凋亡率、线粒体膜电位的明显变化,但能导致胞内游离Ca2+浓度明显上升和Ca2+-Mg2+-ATP酶活性明显降低。预先微波辐照能够明显减弱γ射线引起的胞内游离Ca2+浓度和Ca2+-Mg2+-ATP酶活性改变。

[ Objective ] To explore the effects of pre-exposure with microwave on y-rays induced apoptosis, mitochondrion membrane potential （ MMP ）, intracellular Ca^2＋ concentration and Ca^2＋-Mg^2＋-ATPase activity in mouse bone marrow stromal cells. [ Methods ] Primarily cultured mouse bone marrow stromal cells were randomly divided into control group, microwave alone group, T-rays group and combined exposure group. The microwave alone and combined exposure groups were exposed to 12 μW/cm^2 microwave I h a day for 7 days. The T-rays alone and combined exposure groups were subsequently exposed to 5 Gy ^60Co T-rays on the 8th day. Ca^2＋ concentration and MMP were detected by a flow cytometry（ FCM ）. Apoptosis was detected by Annexin V-FITC/PI, and Ca^2＋-Mg^2＋-ATPase activities were analyzed by a commercial kit. [ Results ] There were no significantly differences between different groups in apoptosis and MMP. 24 h after y-rays irradiation, the Ca^2＋ concentrations of the microwave alone, the y-rays alone and the combined exposure groups were statistically higher than those of the control group（ P〈0.05 ）, while Ca^2＋-Mg^2＋-ATPase activities were statistically lower than those of the control group（ P〈0.05 ）. Compared with the T-rays alone group, Ca2. concentrations of the combined exposure group significantly decreased （ P 〈 0.05 ） and Ca^2＋-Mg^2＋-ATPase activity statistically increased （ P 〈 0.05 ）. [ Conclusion ] Under the experimental condition, microwave radiation （900 MHz, 12 μW/cm^2） and 5 Gy γ-rays did not induce evident changes in apoptosis and MMP; but did induce an increase of Ca^2＋ concentrations and a decrease of Ca^2＋-Mg^2＋-ATPase activity. Pre-exposure with microwave could significantly decrease T-rays induced changes in Ca^2＋ concentration and Ca^2＋-Mg^2＋-ATPase activity.