高尿酸对大鼠认知功能的影响及机制研究

发布时间：2018-04-11 00:08

本文选题：高尿酸 + 学习记忆　；参考：《四川医科大学》2015年硕士论文

【摘要】：目的:观察高尿酸血症(hyperuricemia,HUA)对成年大鼠认知功能(cognitive function)的影响,探究HUA影响认知功能的具体机制。方法:健康、成年(8周龄)雄性SD大鼠75只,体重200±20 g。随机分为三组:空白对照组,蒸馏水组,高尿酸组,25只/组。采用酵母膏联合乙胺丁醇(尿酸酶抑制剂)灌胃法建立高尿酸血症动物模型,空白组不做任何处理,蒸馏水组灌胃与高尿酸组等量的蒸馏水。每天选取固定时间点进行灌胃操作,每周末选取固定时间点取眼球血测定各组大鼠血尿酸浓度。第7周末,应用Morris水迷宫实验检测大鼠学习记忆能力(逃避潜伏期、跨越原平台次数)(17只/组),然后随机选取大鼠9只/组,分离其海马组织进行匀浆,取上清液测定海马组织中丙二醛(MDA),谷胱甘肽过氧化物酶(GSH-Px),抗超氧阴离子(ASAFR)及过氧化物歧化酶(SOD)活力等氧化应激指标,将剩余大鼠海马组织(8只/组)进行HE染色,光镜下观察海马区神经元细胞形态学结构,TUNEL法(细胞凋亡末端标记法)观察海马区锥形细胞凋亡情况,计数凋亡指数(AI%)。结果:1.高尿酸模型:第三周末高尿酸组大鼠的尿酸水平已经达到285μmol/L,以后一直保持高尿酸水平,表明已经造模成功;2.Morris水迷宫实验:1)随着训练时间的延长,各组大鼠定位航行实验时间缩短;在同一时间段,与空白组和蒸馏水组比较,高尿酸组大鼠寻找平台的平均逃避潜伏期无明显缩短(P0.05);2)与空白组和蒸馏水组相比,高尿酸组空间探索实验穿越平台次数明显增多,但差异无统计学意义(P0.05);3.氧化应激指标:与空白组和蒸馏水组相比,高尿酸组大鼠海马组织中MDA含量明显降低(P0.05);GSH-Px,ASAFR,SOD含量明显增高(P0.05);4.病理学变化:HE染色后光镜下观察空白组、蒸馏水组及高尿酸组大鼠海马神经元细胞形态、大小基本正常,呈圆形、椭圆形状,排列紧密,锥形细胞数目无明显减少,细胞核淡蓝色染色,着色较均匀,核仁清晰可见,核膜完整。未见细胞水肿,无明显核固缩及核碎裂等病变细胞,三组比较无明显差异。TUNEL细胞凋亡检测法显示,各组大鼠海马区未见明显锥形细胞凋亡,相比空白组和蒸馏水组,高尿酸组凋亡指数(AI%)亦无明显减少(P0.05)。结论:1.通过酵母膏联合乙胺丁醇灌胃法制作高尿酸血症大鼠模型,操作简单可行,与人体形成高尿酸血症的病理生理过程极为相似,是目前研究高尿酸血症及其相关疾病较为稳定且理想的动物模型;2.5W高尿酸水平未见对实验大鼠学习记忆能力有明显影响;3.罹患5W高尿酸血症能有效减少有害氧化应激自由基的产生,增加自由基清除率,减轻氧化应激反应带来的损伤;4.5W高尿酸水平未见大鼠海马区神经元细胞明显病理学改变。
[Abstract]:Aim: to observe the effect of hyperuricemia on cognitive function in adult rats and to explore the mechanism of HUA affecting cognitive function.Methods: 75 male Sprague-Dawley rats (body weight 200 卤20 g) were healthy and 8 weeks old.They were randomly divided into three groups: blank control group, distilled water group and high uric acid group.The animal model of hyperuricemia was established by yeast extract combined with ethambutanol (uric acid inhibitor). The blank group was not treated, and the distilled water group was given the same amount of distilled water as the high uric acid group.Fixed time points were selected for gastric perfusion and eyeball blood samples were taken to determine the concentration of uric acid in each group.At the end of the 7th week, Morris water maze test was used to detect the ability of learning and memory (escape latency, number of times across the original platform) in 17 rats / group, and then 9 rats were randomly selected for homogenization of hippocampal tissue.The activity of malondialdehyde (MDA), glutathione peroxidase (GSH-PxX), anti-superoxide anion (ASAFR) and superoxide dismutase (SOD) in hippocampus were determined by HE staining.The morphological structure of hippocampal neurons was observed under light microscope. The apoptosis of conical cells in hippocampal area was observed by Tunel method and the apoptotic index was counted.The result is 1: 1.Model of hyperuricemia: at the end of the third week, the uric acid level of the rats in the high uric acid group reached 285 渭 mol / L, and maintained high uric acid level since then, indicating that the model had been successfully made and Morris water maze experiment: 1) with the prolongation of training time,In the high uric acid group, the frequency of space exploration through the platform increased obviously, but the difference was not statistically significant (P 0.05).Index of oxidative stress: compared with blank group and distilled water group, the content of MDA in hippocampus of rats in high uric acid group was significantly lower than that in control group and distilled water group.The pathological changes were observed under light microscope in the blank group, distilled water group and high uric acid group. The hippocampal neurons were normal in size, round in shape, elliptical in shape, compact in arrangement, and no significant decrease in the number of conical cells.The nuclei were stained with light blue with uniform staining, clear nucleolus and intact nuclear membrane.No cell edema, nuclear pyknosis, nuclear fragmentation and other pathological cells were found in the three groups. Tunel cell apoptosis assay showed that there was no obvious cone cell apoptosis in the hippocampus of rats in each group, compared with the blank group and distilled water group.The apoptotic index (AI) in high uric acid group was not significantly decreased (P 0.05).Conclusion 1.The rat model of hyperuricemia was made by yeast extract combined with ethambutanol. The operation was simple and feasible, which was very similar to the pathophysiological process of the formation of hyperuricemia in human body.It is a stable and ideal animal model to study hyperuricemia and its related diseases at present. There is no significant effect on learning and memory ability of experimental rats by 2.5 W hyperuricemia.5 W hyperuricemia could effectively reduce the production of harmful oxidative stress free radicals, increase the free radical clearance rate, and alleviate the damage caused by oxidative stress reaction. There were no obvious pathological changes of neurons in the hippocampal area of rats with hyperuricemia at 4.5 W.
【学位授予单位】：四川医科大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R589.7

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