铅对大鼠CaMKⅡ的影响及行为记忆改变

Effect of lead on the behavior and the express of CaMKⅡ in hippocampus in Wistar rat

目的从钙离子-钙调蛋白依赖性蛋白激酶II(CaMKⅡ)表达等方面探讨不同浓度铅接触与行为记忆改变的关系。方法 32只大鼠随机分为4组:空白组8只,饮双蒸水,模型组24只,分为低、中、高、剂量组,分别按2.4、4.8、9.6 mmol/L的浓度在饮水中添加醋酸铅,60 d后,分别将各组动物进行Morris水迷宫试验;然后收集全血、脑组织原子吸收光谱石墨炉法检测铅含量;采用RT-PCR法和免疫组织化学方法检测脑组织CaMKⅡmRNA及其蛋白表达。结果与空白组比较,各模型组血铅、脑组织铅含量显著增高(P<0.05);Morris水迷宫试验提示模型组大鼠空间定位航行能力下降(P<0.05),铅浓度越高下降越明显(P<0.05);模型组CaMKⅡmRNA及其蛋白表达显著降低(P<0.05)。结论铅能引起铅接触大鼠的行为记忆障碍,且铅接触浓度越高越明显,其机制可能与铅能降低海马区CaMKⅡmRNA及其蛋白依赖性表达等有关。

Objective To investigate the effect of lead on behavior and memory changes and the expression of CalciumCa M-dependent protein kinase II（Ca MKⅡ）in rats. Methods 32 male Wistar rats were chosen and randomly divided into4 groups ： the control group（8 rats）was given distilled water orally, the others 3 groups were given lead acetate orally with 2.4, 4.8 and 9.6 mmol / L. After 60 days, the Water Morris Maze test was used to measure the ability of learning and memory; the graphite heat atomic absorption spectrum method was used to determine the lead concentration in blood and brain; the RT-PCR and immunohistochemistry（IHC） methods were used to determine the expression of Ca MK Ⅱm RNA in hippocampus. Results The ability of dimensional memory in treatment groups had declined significantly compared with control group（P〈0.05）. The lead concentrations in blood and brain in lead poisoned model groups were significantly increased compared with that in the control group（P0.05）. The expression levels of CaMKⅡ mRNA in the lead poisoned model groups were significantly decreased compared with the control group（P〈0.05）. Conclusion The lead（pb）could reduce the behavior and memory. It may be correlated with the increased expression of CaMKⅡ mRNA and its protein in hippocampus area.