亚慢性染铝对大鼠学习记忆及AMPA受体基因表达影响

Effect of subchronic aluminum exposure on learning and memory abilities and the expression of AMPA receptor gene in rats

目的研究亚慢性染铝后对大鼠学习记忆及α-氨基-3-羟基-5-甲基-4-异恶唑丙酸(AMPA)受体基因表达的影响。方法无特定病原体级健康成年雄性SD大鼠36只,按体质量随机分为0.41、0.82、1.23 mg.kg-1.d-1麦芽酚铝[Al(mal)3]组和对照组。染毒组分别腹腔注射Al(mal)30.41、0.82、1.23 mg.kg-1.d-1,对照组给予等容量生理氯化钠溶液。染毒8周后,用Morris水迷宫实验检测大鼠空间学习记忆能力,实时荧光定量聚合酶链反应法检测大鼠海马组织AMPA受体亚单位GluR-1、GluR-2、GluR-3基因表达情况。结果水迷宫结果表明,与对照组比较,0.82、1.23mg.kg-1Al(mal)3组大鼠找到平台时间延长(P<0.05),并且目标象限停留时间缩短(P<0.05);1.23 mg.kg-1.d-1Al(mal)3组穿越平台次数减少(P<0.05)。基因检测表明,与对照组比较,3个Al(mal)3组GluR-1、GluR-2基因表达水平均降低(P<0.01);0.82、1.23 mg.kg-1.d-1Al(mal)3组GluR-3基因表达也降低(P<0.01)。结论亚慢性染铝可使大鼠学习记忆能力下降,其机制可能与大鼠海马AMPA受体各亚基基因表达改变有关。

Objective To study the effects of subchronic aluminum exposure on learning and memory abilities and the ex- pression of AMPA receptor gene in rats. Methods Thirty-six specific pathogen free male SD rats were randomly divided into 4 groups, which included a control group, 0. 41, 0. 82 and i. 23 mg ·kg^-1·d^-1 aluminum-maltolate[ Al（mal）3 ] groups. The exposure groups were treated by intraperitoneal injection for 8 weeks. Morris water maze test was performed to test the learning and memory abilities of rats, and RT-PCR（ real-time polymerase chain reaction） was used to test the gene expression of GluR-1, GluR-2, GluR-3 of AMPA receptor. Results Compared with that of the control group, learning and memory capability test sug- gested that, the platform time of 0. 82, 1.23 mg ·kg^-1·d^-1 Al（mal）3 groups showed significantly prolonged （P 〈0. 05）; and the time spent in the target quadrant in 0. 82, 1.23 mg ·kg^-1·d^-1 A1 （mal） 3 groups was significantly shorter （ P 〈 0. 05 ） ; and the frequency of passing through the platform in rats of 1.23 mg ·kg^-1·d^-1 Al（mal） 3 group was significantly reduced （P 〈 0.05） ; and the gene result showed that GluR-1 and GluR-2 in all the AI（real） 3 groups were gradually decreased（ P 〈 0. 01 ）, while GluR-3 in 0. 82, 1.23 mg·kg^-1·d^-1Al（mal）3 groups also decreased （P 〈0.01 ）. Conclusion Al（mal）3 could induce learning and memory disorder and decrease in rats, its mechanism could be correlated with the expression changes of AMPA receptor gene.