β淀粉样肽及冈田酸对大鼠脑内突触素和发动蛋白Ⅰ表达的影响

Influence of beta-amyloid peptide and Okadaic acid on expressions of synaptophysin and dynamin Ⅰ in rat brain

目的:探讨β淀粉样肽(Aβ)及冈田酸(OA)对大鼠学习记忆能力及脑内突触素和发动蛋白Ⅰ的表达影响。方法:采用立体定向方法将Aβ1-42及OA分别注入SD大鼠双侧海马CA1区,2个月后水迷宫实验检测大鼠学习记忆能力,Western印迹及实时聚合酶链反应(real-time PCR)检测大鼠脑组织中突触素和发动蛋白及mRNA表达水平。结果:与对照组相比,Aβ注射组、OA注射组及Aβ+OA共同注射组均能引起大鼠学习记忆能力降低,各组脑组织中突触素、发动蛋白Ⅰ及mRNA表达均降低(P<0.01),其中以Aβ+OA共同注射组改变尤为明显。结论:Aβ和OA均可降低大鼠学习记忆能力,降低突触素和发动蛋白Ⅰ的表达,该改变可能与AD发病机制中学习记忆能力减退有关。

Objective：To investigate the influence of beta-amyloid peptide（Aβ） and Okadaic acid（OA） on the learning and memory abilities of rats and the expressions of synaptophysin and dynamin Ⅰ in rat brains.Method：Aβ1-42 or OA was injected into the bilateral hippocampus CA1 of SD rats,and learning and memory abilities were evaluated at two months after injection;the protein and mRNA levels of synaptophysin and dynamin Ⅰ were surveyed by Western blotting and real-time PCR,respectively.Result：Significant reduction of synaptophysin and dynamin Ⅰ at protein or mRNA level,and impaired learning and spatial memory were observed in rats after injections of Aβ,OA and Aβ＋OA as compared with controls（P 0.01）,in which the group of Aβ＋OA showed more obvious changes.Conclusion：Aβ1-42 and OA could decrease the learning and memory abilities of rats and inhibit the expressions of synaptophysin and dynamin Ⅰ in the rat brains,which might be a mechanism in connection with cognitive deficit of AD.