丙烯腈对蝾螈睾丸精原细胞DNA的诱导损伤

DNA Damage on Newt Testicle Spermatogonia Induced by Acrylonitrile

目的探讨丙烯腈(ACN)对睾丸精原细胞DNA的损伤作用及经肝微粒体酶活化前后该损伤程度的差异。方法用体外培养方法分离蝾螈睾丸精原细胞,不同浓度(0,0.1,0.4,0.8,1.6μmol/ml)ACN染毒3 h,每个浓度分活化组(加S9)和非活化组(不加S9),另设2个阳性对照组(丝裂霉素C,1.6μg/ml,加S9)和(环磷酰胺,80μg/ml,不加S9),用单细胞凝胶电泳法检测DNA损伤程度。结果未活化ACN浓度≥0.8μmol/ml及活化后ACN浓度≥0.4μmol/ml时,蝾螈精原细胞DNA损伤程度明显升高,彗星发生率、长尾彗星率及彗星细胞平均尾长均明显高于对照组(P<0.05),并存在剂量-反应关系,经S9活化后,ACN对DNA损伤程度比同浓度未活化组明显增强。结论ACN能诱导蝾螈睾丸精原细胞DNA损伤,并且经肝微粒体酶活化后损伤能力明显增强。

Objective To explore acrylonitrile （ACN） induced DNA damage on Newt spermatogonia, and to compare the difference in DNA damages before and after microsomal enzyme activation. Methods Newt spermatogonia were isolated by in vitro cultivation and exposed to ACN for 3 h at concentration of 0, 0.1, 0.4, 0.8, 1.6 μmol/ml respectively. Each concentration included active and non-active groups. The DNA damages were detected by dingle cell gel electrophoresis （SCGE）. Results The results showed that the DNA damage on Newt spermatogonla was significantly increased in groups ≥0.8 μmol/ml non-active ACN and ≥0. 4μmol/ml active ACN, the rate of comets, the rate of long tail comets and the average length of comet cell tail in these groups were significantly higher than those of the control groups （P〈0.05） showing dose- response relationship. After activation, the DNA damage induced by ACN was much more enhanced than that of nonactive at the same concentration. Conclusions The results show that ACN and its metabolites could induce damage on DNA in testicular spermatogonia. The toxicity of its metabolites might be higher than ACN itself after ACN is metabolized by microsomal enzyme.