PCB153对原代培养大鼠睾丸支持细胞SOD活性、DNA损伤及凋亡的影响

The effect of SOD activity,DNA damage and apoptosis induced by PCB153 on cultured rat Sertoli cells

目的:探讨2,2′,4,4′,5-五氯联苯(2,2′,4,4′,5-hexachlorobiphenyl,PCB153)暴露对原代培养大鼠睾丸支持细胞(Sertoli cells,SC)超氧化物歧化酶(superoxide dismutase,SOD)活性、DNA损伤、细胞凋亡的影响以及抗氧化剂N-乙酰半胱氨酸(N-acetyl-L-cysteine,NAC)的干预作用。方法:原代培养出生18～20d雄性SD大鼠的睾丸支持细胞,设PCB153不同浓度的染毒组(加入10、20、30μmol/L PCB153),NAC组(以300μmol/L NAC预处理1h后加入30μmol/L PCB153),和对照组(加入与PCB153最大染毒量等体积的DMSO),各组细胞经上述处理后继续培养24h,用SOD试剂盒测定各组细胞SOD活性,彗星实验测定DNA损伤程度,流式细胞术检测细胞凋亡,细胞荧光标记观察凋亡形态。结果:染毒24h后,大鼠睾丸支持细胞SOD活性随着PCB153染毒剂量的升高而降低,20、30μmol/L染毒组显著低于对照组(P<0.05),NAC预处理可提升SOD活性(P<0.05)。各PCB153处理组及NAC预处理组与对照组相比,DNA损伤间的差异均无统计学意义(P>0.05),细胞凋亡率则均显著增加(P<0.05),NAC预处理可降低PCB153所致的凋亡率(P<0.05)。结论:10～30μmol/L PCB153染毒24h可诱导的原代培养大鼠SCSOD活性降低,细胞凋亡增加,但并未引起DNA损伤,NAC预处理具有保护作用。

OBJECTIVE：To explore the changes of superoxide dismutase（SOD） activity,DNA damage and apoptosis of cultured rat Sertoli cells after exposure to 2,2＇,4,4＇,5-hexachlorobiphenyl（PCB153）,and the effect of N-acetyl-L-cysteine（NAC） pre-treatment.METHODS：Sertoli cells were isolated from 18- to 20-day-old male Sprague-Dawley rats.Contaminated groups were exposed to PCB153 at the doses of 10,20,30μmol/L.NAC group was pre-treated with 300μmol/L NAC for 1h,then exposed to 30μmol/L PCB153.Control group was exposed to DMSO with the volume equal to the highest concentration of PCB153.Then all groups were cultured for 24 h.SOD activity,DNA damage,apoptosis and morphological examination were determined by SOD assay kit,comet assay,flow cytometry and fluorescence photomicrographs,respectively.RESULTS：After 24 h exposure,SOD activity decreased as the PCB153 dose increased,significant difference was observed between 20,30μmol/L groups and control group.NAC pretreatment was able to increase the activity of SOD.No significant difference was observed between treated groups and control group for comet assay.There was a significant dose -response relationship between the level of PCB153 exposure and the apoptotic rate,NAC pre-treatment was able to decrease the apoptotic rate.CONCLUSION：PCB153 in the concentration of 10-30μmol/L was able to decrease the activity of SOD and induce apoptosis in cultured rat Sertoli cells,while DNA damage was not evident.NAC pre-treatment has protective effect on SOD activity and apoptosis.