多柔比星耳毒性的实验研究

Experimental study on ototoxicity of doxorubicin in rats

目的探讨多柔比星的耳毒性及维生素E(VitE)和泛癸利酮(CoQ10)的保护作用。方法Wistar大鼠46只,随机分为3组,其中A组大鼠18只,腹腔注射多柔比星(doxorubicin,DOX)1mg·kg-1(体重),每周2次,同时给予生理盐水灌胃,共3个月;B组大鼠18只,腹腔注射多柔比星1mg·kg-1(体重),每周2次,共3个月,同时给予CoQ1010mg·kg-1·d-1和VitE50mg·kg-1·d-1灌胃;C组大鼠10只,全程以等量生理盐水替代进行腹腔注射及灌胃。用药前后分别进行听性脑干反应(ABR)检测。提取耳蜗组织总DNA,利用巢式聚合酶链式反应(nestedPCR)检测线粒体DNA4834bp缺失突变的发生情况,PCR产物直接测序。同时测定血清谷光苷肽过氧化物酶活性。结果B组用药后听阈增高(923±1901)dB较A组(2094±1624)dB低,差异有极显著性意义(P<001);B组和C组相比听阈增高,差异无显著性意义;B组内耳组织线粒体DNA4834缺失突变发生率(2308%)较A组(6875%)明显降低,差异有显著性意义(P<005);B组血清谷光苷肽过氧化物酶活性(14094±4258)U比A组(5995±1865)U高,差异有极显著性意义(P<001)。结论长期应用多柔比星可引起大鼠听阈的轻度增高,诱发内耳组织线粒体DNA4834bp缺失突变。CoQ10和VitE可以降低多柔比星对内耳组织的损伤作用。

OBJECTIVE: To investigate the ototoxicity of doxorubicin (DOX) and the protective roles of vitamin E and Coenzyme Q10. METHODS: 46 Wistar rats were randomly divided into 3 groups. There were 18 rats in group A and group B respectively, and 10 rats in group C. The rats in group A and group B were given doxorubicin by intraperitoneal injection twice a week for 3 months, At the same time the rats in group B took vitamin E 50 mg&middotkg -1&middotd-1 and CoQ10 10 mg&middotkg -1&middotd-1 orally but the rats in group A were given saline instead. Group C received only saline. The auditory threshold was measured before and after the drug administrations by auditory brainstem respons (ABR). The inner ear tissues were harvested, and then the mitochondrial DNA was amplified to identify the 4834bp deletion mutation of mitochondrial DNA by nested-primer PCR. The products of PCR were verified by sequencing. The activity of glutathione peroxidase of serum was measured. RESULTS: The auditory threshold elevation of group B (9.23 ± 19.01) dB was significant lower than that of group A (20.94 ± 16.24) dB (P < 0.05). There was no significant difference between group B and group C. The incidence of mitochondrial DNA 4834bp deletion mutation of group B (23.08%) was significant lower than that of group A (68.75%) (P < 0.01). The activity of serum glutathione peroxidase of group B (140.94 ± 42.58) U was markedly higher than that of group A (59.95 ± 18.65) U (P < 0.05). CONCLUSION: The results suggested that long-term DOX therapy could raise the auditory threshold slightly and induce the 4834bp deletion mutation of mitochondrial DNA of rat. Vitamin E and CoQ10 could markedly inhibit this kind of ototoxicity of DOX.