【摘要】 目的:观察SD大鼠海马立体定向注射β-淀粉样蛋白1-40后β位淀粉样前体蛋白裂解酶1mRNA表达的变化及加减地黄饮子对其的干预作用。方法:①实验于2005-09/2006-09在齐齐哈尔医学院医药科学研究所完成。②选用100只SD大鼠随机分为空白对照组、假手术对照组、模型对照组、盐酸多奈哌齐组、加减地黄饮子组共5组,每组20只。通过海马立体定向注射β-淀粉样蛋白1-40诱导老年性痴呆动物模型。③盐酸多奈哌齐按0.33mg/(kg·d)给药,加减地黄饮子组按1.0g/(kg·d)给药,共给药28d。空白对照组和假手术对照组给予等量生理盐水。④第5周处死大鼠,应用实时定量PCR法检测大脑海马组织β位淀粉样前体蛋白裂解酶1mRNA表达(用2-ΔΔCt表示,Ct为阈循环值,ΔCt=CtBACE1-CtGAPDH,ΔΔCt=ΔCt各干预组-ΔCt空白对照组)。⑤多组间差异的显著性分析用单因素方差分析,组间两两比较运用LSD-t检验。结果:实验选用100只大鼠,每组随机选5只用于抽提大脑海马组织总RNA,因此共有25只大鼠纳入结果分析。β位淀粉样前体蛋白裂解酶12-ΔΔCt值模型组(4.67±0.52)显著高于假手术对照组(1.07±0.08)(P<0.01),表明模型组β位淀粉样前体蛋白裂解酶1mRNA表达上调。盐酸多奈哌齐组(1.80±0.23)和加减地黄饮子组(1.26±0.20)显著低于模型对照组,表明β位淀粉样前体蛋白裂解酶1mRNA表达下调。结论:大鼠大脑海马注射β-淀粉样蛋白1-40后海马组织β位淀粉样前体蛋白裂解酶1mRNA表达水平明显增高,加减地黄饮子提取物可以抑制海马组织β位淀粉样前体蛋白裂解酶1mRNA的表达,从而发挥抗老年性痴呆的作用。更多还原

【Abstract】 AIM:To observe the effect of modified decoction of rehmanniae on β-site amyloid precursor protein(APP) cleaving enzyme(BACE1) mRNA expression in hippocampus tissue of SD rats induced by β-amyloid 1-40 injection into brain.METHODS:①This study was completed at the Medicine Institute of Qiqihar Medical College from September 2005 to September 2006.②Totally 100 SD rats were enrolled and randomly divided into 5 groups with 20 in each,named as blank controls group,sham controls group,model group,Donepezil group and modified decoction of rehmanniae group.Rats were induced by β-amyloid1-40 sterotaxis injection into the bilateral hippocampus for Alzheimer’s disease(AD) model.③Physiological saline was injected into the rats of blank controls group and sham controls group.And 0.33 mg/kg Donepezil was administrated for Donepezil group,while 1.0 g/kg modified decoction of rehmanniae was administrated for experiment group daily,continuously for 28 days.④All rats were sacrificed at the 5th week,BACE1 mRNA expression in hippocampus tissue was assayed by real-time quantitative reverse transcription-PCR(expressed as 2-ΔΔCt,Ct as cycle threshold,ΔCt=CtBACE1-CtGAPDH,ΔΔCt=ΔCtinvervention groups-ΔCtblank controls group).⑤Difference of measurement data among groups were compared with single factor variance analysis,and comparison between two groups was performed with LSD-t test.RESULTS:All 100 rats were adopted and every 5 rats of each group was selected to extract total RNA of hippocampal tissue,thus these 25 rats were involved in the result analysis.The BACE1 mRNA expression was significantly up-regulated in model group compared with the sham group [2-ΔΔCt value:(4.67±0.52),(1.07±0.08),P < 0.01].The BACE1 mRNA expressions in modified decoction of rehmanniae group and Donepezil group were down-regulated compared with the model group [(1.80±0.23),(1.26±0.20)].CONCLUSION:β-amyloid1-40 injection into the bilateral hippocampus can lead to the increased expression of BACE1 mRNA in hippocampus tissue.Modified decoction of rehmanniae may down-regulate expression of BACE1 mRNA and can be used as an effective drug for AD.更多还原