中文摘要：

目的研究铅暴露对不同生长阶段SD雄性大鼠脑组织铅、铁水平及DNA氧化损伤的影响。方法将12只SPF级SD雌性大鼠随机分为3组，分别为空白对照（去离子水）组和低（0．8g／L）、高（1．5g／L）剂量乙酸铅染毒组，每组4只。采用自由饮水方式进行染毒，自妊娠前10d至仔鼠断乳（出生后21d）。待断乳后，每组选取21只雄性仔鼠，相应各组分别自由饮用去离子水和0-3、0．9g／L乙酸铅溶液。仔鼠分别饲养至断乳（21d）、中年（12个月）、老年（18个月）时，检测脑组织中铅、铁和8一羟基脱氧鸟苷（8-hydroxy－2’－deoxyguanosine，8-OHdG）的水平。结果在同一生长阶段，随着铅染毒剂量的升高，大鼠脑铅、脑铁及脑组织8-OHdG水平均增加。线性回归分析结果显示，在断乳期和老年期，大鼠脑铁、脑8-OHdG水平随着脑铅水平的升高而上升（P〈0．05）；同时，脑铅、脑铁联合作用使大鼠脑8-OHdG水平升高（P〈0．05）。而中年期无明显改变。在空白对照组和各剂量铅染毒组中，随着铅染毒时间的延长，大鼠脑铅、脑铁水平均增高（P〈0．05）。空白对照组中，脑8-OHdG水平在中年、老年期增高（P〈0．05）；低剂量组改变不明显；高剂量组在老年期明显升高（P〈0．05），中年期改变不明显。结论铅暴露可致SD大鼠脑组织铁过载及DNA氧化损伤。

英文摘要：

Objective To investigate the brain iron,brain DNA and oxidative stress of the SD rat brain in different development stages. Methods SPF female and male Sprague-Dawley rats were respectively randomly divided into three groups：control,low lead-exposed, high lead-exposed. Lead-exposed female rats drank 0.8,1.5 g/L lead acetate solutions during the first ten-day of pregnancy until weaning and then the male pups received 0.3,0.9 g/L lead acetate solution depending on their group. When pups grew up to weaning （21 days）,mid-age （ten months） and old-age （18 months） , the DNA of brain tissue were extracted,digested and the contents of 8-OHdG were determined by ELISA. The offspring were measured the lead and iron concentration of brain by ICP-AES. Results At the same growth stage,the brain lead, brain iron and 8-OHdG contents were higher in different lead exposure groups compared with the control. Linear regression showed that the brain iron and the 8-OHdG contents of the brain were higher in different lead exposure groups （P〈0.05）; Brain iron and brain lead could jointly raise the 8-OHdG of brain（P〈0.05）, whether a synergistic effect between brain iron and brain lead needed to be validated. The 8-OHdG contents increased with lead exposure levels at weaning and the old-age （P〈0.05）. In control group,the mid-age and old-age groups were higher than the weaning rats （P〈0.05）. In high lead group, the old-age group was higher than the mid-age and weaning rats （P〈O.05）. There was no significant difference in mid-aged rats. Conclusion Lead exposure may induce iron overload and DNA damage in rat brain.