孕哺期染铅对幼鼠脑微量元素、SOD及细胞凋亡的影响

目的 探讨孕哺期铅暴露所致仔代发育期的神经毒性机制。方法 母鼠从妊娠起始至仔鼠出生后7d染铅，原子吸收石墨炉法及火焰法测定出生后7d仔鼠的血、脑铅及脑组织微量元素铜、锌含量；同时测定脑组织脂质过氧化水平（LPO）及超氧化物歧化酶（SOD）活性；另外应用原位末端标记TUNEL法测定脑海马区及附近皮质细胞凋亡数量的改变。结果 染铅使仔鼠血铅、脑铅水平升高，脑微量元素铜有下降趋势，同时脑LPO水平升高，SOD活性下降，且海马区附近皮质细胞凋亡数量增加，尤其体现在高剂量染铅组。结论 铅的发育神经毒性与中枢神经系统铜等微量元素的改变、抗氧化能力下降及由此所致的细胞凋亡数量增加有关。

Effect of lead exposure during pregnancy and lactation on trace element level, SOD activity and apoptosis in brain of baby-rats

Objective To study the mechanism of neurotoxic effect of lead exposure during pregnancy and lactation on baby-rat.Method The female rats were administrated with lead from pregnancy to(7th) day after delivery,measuring the Pb concentration in blood and Pb,Cu,Zn concentrations in brain of the baby-rats by atomic absorption spectrophotometry,the LPO level and SOD activity in brain were also measured.In addition,meanwhile,the number of apoptotic cells at hippocampus and nearby cortex were also detected by in situ labeling method(TUNEL).Result The results showed that the levels of blood lead and brain lead were increased,the brain Cu concentration seemed to present some decrease trend with the rise of lead level,and there were increase of LPO level and decrease of SOD activity in brains of the baby-rats as well;meanwhile the apoptotic cell number also showed some increase in the hippocampus and its nearby cortex especially in the high dosage group.Conclusion The toxicity of lead on neuron development might related to the change of trace element concentration,reduction of antioxidation ability and increasing apoptosis in brain.