铅对妊娠期及新生期大鼠神经细胞DNA的损伤

Study on DNA damage of neural cells during pregnancy and newborn in lead-induced rats

目的研究妊娠期及新生期母体铅暴露对新生仔鼠神经细胞DNA损伤作用,以进一步揭示铅的神经毒性作用机制。方法SD孕鼠随机分为6组,妊娠第1d至新生仔鼠出生后第28d进行醋酸铅[Pb(CH3COOH)2]0,50,80,120,200mg/(kg·bw)连续经口灌胃染毒。取出生8d的新生仔鼠的海马和皮层细胞,进行单细胞分离后,采用单细胞凝胶电泳(彗星试验)检测细胞,观察DNA迁移长度及拖尾细胞百分率。结果各剂量醋酸铅均可引起神经细胞DNA的单链断裂,出现彗星拖尾,其拖尾细胞百分率DNA迁移长度均随醋酸铅剂量的增加而增长,各剂量与阴性对照的结果比较均差异有统计学意义(P<0.05)。结论醋酸铅可引起神经细胞DNA损伤,并与剂量呈正相关;单细胞凝胶电泳是检测神经细胞遗传毒性及细胞凋亡的有效方法。

Objective To study the effect of lead exposure during pregnancy and newborn on DNA damage in the neural cells of newborn rat.Methods Pregnant rats were divided into six groups randomly,and were treated with lead acetate at the dosage of 0,50,80,120,150,200?mg/(kg·bw) by gastric feeding from day 1 of gestation to day 8 after delivery.The single cells were dissociated from hippocamous and cerbral cortex of newborn rats at 8 days old.Then single cell gel electrophoresis test was used to measure the DNA damage.Comet length means and percentage of tailed-cell were observed.Results: The lead acetate could induce the breakage of DNA single strand and resulted in comet cells with tail in every treatment dosage groups compared with control group (P<0.05).Both the number of comet cells and the length of DNA migration increased with increasing of dosage of lead acetate. Conclusion Lead acetate might cause DNA damage of rat neural cells.The damage was positive correlative with the lead dosage.The single cell gel electrophoresis test was a useful tool for determining the genotoxicity and apoposis of neural cells.