丹参酮对D半乳糖Aβ140致痴呆大鼠海马内Aβ及AChE影响.docVIP

丹参酮对D半乳糖Aβ140致痴呆大鼠海马内Aβ及AChE影响 　【摘要】 目的 探讨丹参酮对D半乳糖Aβ140致复合痴呆模型大鼠海马内β淀粉样蛋白(Aβ)和乙酰胆碱酯酶(AChE) 表达的影响。方法 实验动物随机分成AD模型组、丹参酮治疗组和溶媒对照组。采用免疫组织化学和酶组织化学方法，分别观察大鼠海马内Aβ和AChE表达的变化。结果 AD模型组大鼠海马内Aβir细胞数显著增多，平均光密度增强;AChE阳性神经纤维受损，光密度下降 (含阳性面积百分比和光密度);与溶媒对照组比较差异显著(Plt;0.01)。丹参酮处理后，Aβir细胞数明显减少，光密度也下降;AChE阳性神经纤维密度增强，与AD模型组比较差异有显著性意义(Plt;0.01)。结论 丹参酮改善D半乳糖Aβ140致复合痴呆大鼠学习记忆障碍的作用机制，可能与降低海马内Aβ的表达而保护脑内胆碱能神经有关。 【关键词】 丹参酮;D半乳糖;β淀粉样肽蛋白;乙酰胆碱酯酶;海马 【Abstract】 Objective To investigate influence of tanshinone on levels of βamyloid (Aβ) and acetylcholinesterase (AchE) in hippocampus of dementia model rats induced by Dgalactose combination with Aβ140.Methods Rats were randomly divided into Alzheimer′s disease (AD) model, tanshinone treatment, and solvent control groups. The expression of Aβ and AChE in rats hippocampus were respectively observed by immunohistochemical and enzymehistochemical methods. Results Aβir cells count and the average optical density of AD rats in the hippocampus were obviously increased, AChE positive nervous fibers damaged, optical density of AChE positive nervous fibers were significantly decreased in AD model group compared with solvent control group. After treated with tanshinone, Aβir cells count and the optical density obviously decreased, AChEpositive nervous fibers were significantly increased compared with AD model group. Conclusions Mechanism of tanshinone on improving learning and memory impairment dementia model rats induced by Dgalactose combination with Aβ140 might be related to decreasing expression of Aβ in hippocampus and protecting cholinergic nerves in brain. 　　【Key words】 Tanshinone; Dgalactose; βamyloid peptide protein (Aβ); Acetylcholinesterase (AChE); Hippocampus 　 阿尔茨海默病(AD)〔1〕是严重影响老年人健康的常见病、多发病，在欧、美等国家已成为继心血管病、肿瘤及中风之后的第4位死亡原因。各种原因导致的中枢神经系统内β淀粉样前体蛋白(APP)的过多表达，APP被降解导致过量的β淀粉样蛋白(Aβ)产生是启动AD发病的关键因素。Aβ是AD患者脑内老年斑的主要成分，凝聚态的Aβ具有神经毒性被认为是细胞凋亡过程的诱导因素〔2，3〕。AD患者表现出中枢胆碱能系统功能紊乱，神经递质乙酰胆碱 (ACh) 及其合成酶胆碱乙酰化酶(ChAc)缺失的程度与AD密切相关〔4〕。有报道，丹参酮ⅡA和ⅡB能减少小鼠