金属硫蛋白对γ射线和丝裂霉素C致遗传损伤的拮抗作用

目的探讨兔肝锌金属硫蛋白（Zn－MT）对γ射线和丝裂霉素C（MMC）所致遗传损伤的桔抗作用。方法应用体内外微核试验和单细胞凝胶电泳法分别检测γ射线照射或MMC处理前后给以Zn-MT对微核形成或DNA链断裂的影响。结果664μg／kg剂量Zn-MT对5Gyγ射线诱发的小鼠骨髓微核形成有抑制作用。10、50μg／mlZn-MT能持抗1和3Gyγ射线及0．3μg／mlMMC诱发的g12细胞双核微核细胞率升高,50μg／mlZn-MT能使1Gyγ射线诱发的链断裂减少。结论兔肝ZnMT对γ射线和MMC所致遗传损伤有一定拮抗作用。

Antagonistic effects of metallothionein on genetic damage caused by gamma-rays and mitomycin C

OBJECTIVE: To study the antagonistic effects of metallothionein (Zn-MT)on genetic damage caused by gamma-rays and mitomycin C (MMC) in the liver of rabbits. METHODS: Micronucleus test and DNA strand breaks were determined in vitro and in vivo with single-cell gel electrophoresis assay to observe the effects of Zn-MT on the micronucleus formation and cleavage of DNA chain before and after gamma-rays radiation and MMC treatment. RESULTS: A dose of 664 microg/kg of Zn-MT could inhibit micronucleus formation in the bone marrow of the mice induced by 5 Gy gamma-rays radiation (P < 0.05). Concentrations of 10 and 50 microg/ml Zn-MT could antagonize the increase in bimicronucleus frequency in g12 cells induced by 1 and 3 Gy gamma-rays radiation and 0.3 microg/ml MMC treatment (P < 0.05 or P < 0.01). A dose of 50 microg/ml Zn-MT could reduce the DNA single strand breaks caused by 1 Gy gamma-rays radiation, but without statistical significance (P > 0.05). CONCLUSION: Zn-MT could antagonize the genetic damage to certain extent in the liver of the rabbits caused by gamma-rays radiation and MMC treatment.