目的:研究松果菊苷( ECH)对阿尔采末病( AD)模型大鼠海马、大脑皮质细胞外液中单胺类神经递质水平的影响,为ECH改善学习记忆力提供理论依据。方法60只 SD大鼠随机分为模型组、ECH 低、中、高剂量组、阳性药石杉碱甲组以及假手术组。采用腹腔内注射 D-半乳糖,并在右侧海马内注射Aβ25-35复制AD 模型。 Morris 水迷宫评价各组大鼠学习记忆能力,应用脑双位点双通道同步微透析采样技术,联合运用高效液相-电化学法测定大鼠海马和皮质细胞外液中 NA、DA、5-HT 的含量。结果水迷宫结果显示,与假手术组相比, AD 模型组大鼠逃避潜伏期明显延长( P 〈0.05),停留在原平台象限时间明显缩短(P〈0.05);与模型组相比,ECH低、中、高剂量组均使大鼠学习记忆能力有不同程度的提高,ECH组逃避潜伏期明显缩短(P〈0.05),停留在原平台象限时间明显延长( P〈0.05)。同时,模型组较假手术组大脑皮质、海马中的 NA、DA、5-HT 明显降低( P 〈0.05);ECH组较模型组脑内单胺类神经递质水平恢复至接近正常水平。结论 ECH可以改善AD大鼠学习记忆力,并且明显升高海马、皮质细胞外液中单胺类神经递质的含量,具有一定的抗AD作用。并且 ECH 中、高剂量组、阳性药石杉碱甲组在提高学习记忆能力方面作用优于ECH低剂量组。
Aim To investigate the influence of echi-nacoside ( ECH ) on monoaminergic neurotransmitter extracellular of the hippocampus and cerebral cortex in rat model of Alzheimer′s disease ( AD) , and ultimately to provide a theoretical basis for ECH′s improving the ability of learning and memory. Methods 60 male SD rats were randomly divided into 6 groups with 10 rats in each group : sham operation group, model, ECH groups of low, medium and high doses (10, 20, 40μg ·g-1 ·d-1 ) , and Hup A ( Huperzine A, 0. 02 μg· g-1·d-1) group. The AD rat model was established by abdominal cavity injection with D-galactose and uni-laterally injected with amyloid beta-protein fragment 25-35 ( Aβ25-35 ) into the right hippocampus. Morris wa-ter maze test was used to study the animals′ ability of spatial learning and memory. The synchronous dual-probe dual-channel brain microdialysis sampling tech-nology was applied to collect dialysates from different encephalic areas continuously, and combined with HPLC electrochemical detection were used to measure the extracellular levels of norepinephrine ( NE) , dopa-mine (DA), 5-serotonin (5-HT). Results 1. Com-pared with the sham operation group, the mean escape latency of the model group was significantly prolonged ( P〈0. 05 ) , and the time that rats were in the plat-form quadrant was significantly shortened ( P〈0. 05 );on the contrary, compared with the model group, the mean escape latency of ECH groups were significantly shortened ( P〈0. 05 ) , and the time that rats were in the platform quadrant was significantly extended ( P〈0. 05). 2. Compared with the sham operation group, the contents of NE,DA and 5-HT were significantly de-creased in the model group ( P 〈0. 05 ) . However, compared with the model group , ECH could improve the concentrations of NE, DA, 5-HT in the hippocam-pus and cerebral cortex, and these monoamine levels of the brain regions were restored to near control. Co