应用UDS和微核试验评价磷酸镁骨黏合剂的遗传毒理效应

Genetic tonxicity evaluation of magnesium phosphate cement by UDS test and micronucleus test

目的从遗传毒理学角度探讨磷酸镁骨黏合剂(magnesium phosphate cement,MPC)的遗传毒理学特性,为其在骨缺损修复领域的临床应用提供依据。方法将磷酸镁骨黏合剂制备浸提液,生理盐水作为阴性对照,采用程序外DNA合成(unscheduled DNA synthesis,UDS)检测法,硫酸镍为阳性对照,对渗入氚标记的胸腺嘧啶核苷(3H-TdR)的人外周血淋巴细胞液DNA做液体闪烁计数,测定3H-TdR掺入量的每分钟放射计数(radio counting per minute,CPM)值;采用小鼠骨髓嗜多染红细胞核试验,阳性对照组为环磷酰胺(CPA),测试其对小鼠股骨骨髓嗜多染红细胞的微核率。结果UDS试验结果显示:实验组(MPC浸提液)的CPM均值为35.98,而阴性对照组的CPM值仅为14.75,实验组不同浓度MPC浸出液的CPM值均略高于阴性对照组(生理盐水组),但差异无显著的统计学意义(P>0.05)。然而,考虑实验组MPC浸提液的CPM均值(35.98)远低于阳性对照组(不同浓度NiSO4)的CPM均值(415.38),且有显著的统计学差异(P<0.01)。因此,可以认为MPC浸提液不会引起DNA损伤。微核试验的结果显示:实验组引起股骨骨髓嗜多染红细胞的微核率与生理盐水阴性组比较,差异无显著意义(P>0.05),而实验组与阳性组之间存在明显差异(P<0.05)。结论磷酸镁骨黏合剂不会引起人外周血淋巴细胞程序外DNA合成增加,也不会引起骨髓嗜多染红细胞微核率增加。提示此骨黏合剂不会引起DNA损伤,也不会引起骨髓细胞突变作用。

Objective To study the inherent toxicology of magnesium phosphate cement（MPC） for its clinical use. Methods The MPC diffusion was detected through unscheduled DNA synthesis （UDS） test. Physiological saline and NiSO4 were used as the negative and positive control, respectively. The marker of observation was the radio counting per minute （CPM） in human peripheral blood lymphocyte, which contained ^3H-TdR. Physiological saline and CPA were used in the micronucleis test as the negative and positive control, respectively. The marker of observation was the mutagenesis rate of murine typhoid salmonella （MR）. Results The results of UDS test showed that the CPM of the negative control group （the saline group）, was 14.75. However, the mean of CPM of different concentration MPC leachate in the experimental group was 35.98, a little higher than CPM in the negative control group. There was no significant difference （P 〉 0.05） between the negative control group and the experimental group. Because the CPM of the experimental group （35.98） was much lower than the CPM of the positive control group （415.38）. Therefore, we considered that MPC did not cause the damage of DNA. The micronucleus test showed that there was no significant difference between the mutagenesis rates of murine typhoid salmonella in different concentration MPC leachate and the negative control group （P 〉 0. 05）, while the MR showed significant difference between the positive control group and the experimental group （P〈0.05）. Conclusions MPC does not cause the increase in the unscheduled DNA synthesis of human peripheral blood lymphocyte and the back mutation in murine typhoid salmonella, which showed that this cement would not cause gene mutation and DNA damage.