轻度认知功能障碍大鼠模型评价及G蛋白偶联受体激酶2的作用  

Establishment and evaluation of mild cognitive dysfunction models in elderly rats and roles of G protein-coupled receptor kinase 2

作　　者：柏慧[1] 胡世莲[1] 徐维平[1] 孙梦雯[1] 周树生[1] 顾辨辨[1] 严光[1] 

机构地区：[1]安徽医科大学附属省立医院老年医学科,合肥230001

出　　处：《中华老年医学杂志》2013年第4期435-439,共5页Chinese Journal of Geriatrics

基　　金：安徽省国际科技合作计划项目（11030603025）

摘　　要：目的探讨轻度认知功能障碍（MCI）大鼠模型的制备方法，研究大鼠轻度认知功能障碍的病理生理特点。方法14～18月龄SD大鼠随机分为模型组（20只）和假手术组（20只），模型组造成双侧颈总动脉（CCA）重度狭窄，假手术组只分离双侧颈总动脉但不结扎。造模后30天从Morris水迷宫实验、脑组织的病理形态学及电镜观察、逆转录聚合酶链反应技术（RT-PCR）检测海马组织中G蛋白偶联受体激酶2（GRK2）mRNA表达、蛋白免疫印迹法（Westernblot）检测海马组织GRK2蛋白表达等方面评价模型组和假手术组大鼠。结果模型组大鼠的死亡率为10％，死亡率较低。病理形态学及超微结构显示，假手术组大鼠海马组织细胞结构较正常，而模型组大鼠海马CAl区椎体细胞缺血脱失，排列较疏松，部分细胞出现胞核固缩、深染，脑白质未见明显梗死灶，部分白质纤维变稀疏且走行较紊乱变，出现核仁变小靠边，胞浆电子密度增高，偶见脂褐素，粗面内质网及高尔基体扩张，胞浆游离核糖体增多，线粒体肿胀，部分出现空泡。Morris水迷宫测试结果显示，模型组大鼠平均逃避潜伏期均较假手术组大鼠延长（P〈0．05），空间探索实验结果显示模型组大鼠目标第1次穿原平台所在位置平均时间为（36．80±7．68）S，明显长于假手术组的平均时间（20．87±6．16）s；模型组大鼠60秒平均穿越原平台次数为（1．43±0．51）次，显著少于假手术组的（3．10±1．45）次，差异均具有统计学意义（P〈0．05）。模型组大鼠海马组织中GRK2mRNA和GRK2蛋白相对表达量均较假手术组明显增强（P〈0．05）。结论CCA重度狭窄大鼠模型的稳定性和可重复性较好，可以作为MCI动物模型。模型组大鼠细胞形态和超微结构均出现较明显病理学改变，且认知功能有轻度损害。GRK2可能在MCI发生发展过程中起到重�Objective To establish mild cognitive dysfunction （MCI） models in elderly rats, and to investigate the pathophysiological features. Methods Totally 40 SD rats （14- to 18-month- old） were randomly divided into 2 groups： the model group （n=20） and the sham operation group （n = 20）. Bilateral carotid artery stenosis was prepared in the model group while bilateral carotid artery was seperated with no bilateral narrowing in the sham operation group. 30 days after the operation, Morris water maze test was performed, pathomorphological and electron microscopic observations of the cerebral tissue were examined and the expression of G protein-coupled receptor kinase 2（GRK2） in hippocampus tissue w detected by reverse transcription polymerase chain reaction （RT-PCR） and Western blottin. Results The mortality in model group was only 10%. Pathological morphology and ultrastructure showed that hippocampal tissue structure was almost normal in sham operated group, but in model group group, hippocampal CA1 pyramidal cells were in ischemic demyelination, arranged loose, and part of the cells showed nucleus pyknosis, deeply stained; there was no obvious infarct in white matter, part of the white matter fiber became thinner and disorder, nucleolus became smaller and steped aside, cytoplasmic electron density increased, lipofuscin appeared occasionally.Rough endoplasmic reticulum and Golgi were expanded, cytosolic free ribosomes increased, part of mitochondria became swelled, vacuolated. Morris water maze test results showed that the average escape latency in model group was longer than in sham group （P〈0.05）. In spatial probe test,the average time of crossing the first original platform in model rats was significantly longer than the sham operated group [（36.80±7.68） s vs. （20.87±6.16）s, P〈0. 05]. The average number of crossing the original platform in 60 seconds in model group was significantly less than in sham group（1.43± 0.51 vs. 3.10±1.45, P〈0.05）. The expressiones of GRK2 m

关 键 词：认知障碍 颈动脉狭窄 G蛋白偶联受体激酶2 

分 类 号：R-332[医药卫生] R74