莱菔硫烷对发育早期铅暴露小鼠学习记忆能力及海马组织β淀粉样蛋白表达的影响
Effect of sulforaphane on spatial learning and memory ability and β-amyloid protein level in hippocampus from early lead-exposed mice

目的:探讨莱菔硫烷(SFN)对发育早期铅暴露小鼠空间学习记忆能力和海马组织中β淀粉样蛋白(Aβ)表达的影响。方法:12只SPF级昆明小鼠,其中8只雌鼠分为染毒组(4只)和正常组(4只)。染毒组小鼠饮2 g/L的醋酸铅溶液21 d,正常组小鼠饮无铅去离子水。染毒结束后,按雌？？GA6FA？Ｐ？=2？？GA6FA？？1进行合笼,孕鼠单笼饲养,仔鼠断乳(出生后21 d)后染毒组仔鼠按体重随机分为铅暴露组和SFN干预组(各10只),分开饲养,正常组仔鼠选取10只作为对照组。SFN干预组小鼠用25 mg/kg的SFN进行灌胃处理,铅暴露组小鼠用生理盐水进行灌胃,对照组小鼠自由饮用无铅去离子水,持续4周。干预结束后用Morris水迷宫测试仔鼠空间学习记忆能力,用伏安极谱仪测试仔鼠血液中铅含量,用酶联免疫吸附试剂盒测定仔鼠海马组织中Aβ1-40和Aβ1-42的水平。结果:在水迷宫测试中,各组小鼠的逃避潜伏期有随时间缩短的趋势,且时间因素和分组因素存在交互作用(P<0.05); 与对照组相比,铅暴露组小鼠逃避潜伏期延长,穿越平台次数减少,血铅含量升高,海马组织中Aβ1-40和Aβ1-42的水平增加(P<0.05); SFN干预组小鼠较铅暴露组小鼠逃避潜伏期缩短,穿越平台次数增加,血铅含量、海马组织中Aβ1-40和Aβ1-42的水平降低(P<0.05)。结论:SFN能够降低小鼠在发育早期由于铅暴露引起的血铅含量的增加,减少海马组织中Aβ1-40和Aβ1-42的沉积,改善学习记忆能力。
Aim: To investigate the effect of sulforaphane(SFN)on spatial learning and memory ability and the level of β-amyloid protein(Aβ)in hippocampus from early lead-exposed mice.Methods: In 12 adult Kunming mice, all 8 female mice were randomly divided into two groups by body weight(n=4): the normal group, the lead administrated group. The lead administrated group drank 2 g/L lead acetate aqueous solution for 21 d. The normal group drank lead free deionized water. Then, the mice were mated with 1？？GA6FA？？2 ratio of male to female. After weaning, 10 pups of the normal group were randomly selected as the control group who drank lead-freed deionized water for 4 weeks. Meanwhile, the pups of the lead administrated group were divided into 2 groups by weight randomly(10 in each group):lead-exposed group and SFN group. The mice were subjected to gavage daily for 4 weeks. The mice of lead-exposed group were intervened with normal saline, the mice of SFN group were intervened with 25 mg/kg SFN. After intervention, the spatial learning and memory ability was evaluated by the Morris water maze test. Meanwhile, the lead level in the blood was determined by polarography, and the levels of Aβ1-40 and Aβ1-42 in hippocampus were measured by ELISA.Results: In water maze test, the escape latencies of mice in each group were shortened with time, and there was interactive effect between time factor and group factor(P<0.05). Compared with the mice of the control group, the mice of the lead-exposed group performed worse(P<0.05). In addition, both the blood lead level and the Aβ1-40, Aβ1-42 levels in hippocampus of the mice in the lead-exposed group had significant increase compared with the control group(P<0.05). Moreover, the above indexes in the SFN group were significantly decreased compared with the lead-exposed group(P<0.05).Conclusion: SFN could ameliorate cognitive decline through decreasing the lead level in the