海马AMPARs参与肠易激综合征大鼠中枢敏化

发布时间：2018-01-07 18:08

本文关键词：海马AMPARs参与肠易激综合征大鼠中枢敏化　出处：《福建医科大学》2015年硕士论文　论文类型：学位论文

【摘要】：目的探究海马α-氨基-3-羟基-5-甲基4-异嗯唑丙酸受体(a-amino-3-hydroxy-5-methyl-4-isoxazole-propionate receptor,AMPARs)在肠易激综合征(Irritable bowel syndrome,IBS)慢性功能性内脏痛大鼠中枢敏化的作用及机制,以期揭示IBS慢性功能性内脏痛发病机制,为IBS慢性功能性内脏痛临床防治及药物研发提供新思路。方法新生SD大鼠出生后第3~21天,每天固定时间给予3小时母婴分离心理应激,构建IBS慢性内脏痛模型,对照组大鼠除不行母婴分离外,其他处理方式均与模型组一致。大鼠成年后(8周),通过检测40和60 mm Hg结直肠扩张刺激下腹外斜肌放电反应的方法评估模型成功与否,选痛觉敏化者进行实验。经立体定位置管,海马双侧微量注射不同剂量的AMPARs抑制剂CNQX(10、20、40 nmol,每侧2μl),观察比较给药前后不同压力下腹外斜肌放电反应的差异及药效持续时间。通过Western blot方法检测比较正常和IBS大鼠海马AMPARs亚型(Glu R1,Glu R2)的表达水平;应用离体脑片场电位记录方法观察IBS大鼠海马CA1区长时程增强(long-term potential,LTP)是否易化,并在高频刺激60min后,取海马脑片通过Western blot检测其Glu R1、Glu R2的表达情况。结果①IBS慢性功能性内脏痛大鼠内脏痛敏反应较正常大鼠显著增高。②海马双侧微量注射AMPARs抑制剂CNQX可剂量依赖性抑制大鼠内脏痛敏反应,抑制作用在给药后30min最强,可持续约90min。③与对照组大鼠相比,IBS慢性功能性内脏痛大鼠AMPARs的亚型Glu R2表达量显著增高,然而Glu R1的表达水平却无明显差异。④IBS慢性功能性内脏痛大鼠,高频刺激诱导的海马LTP与正常大鼠相比显著增强。⑤正常和IBS慢性功能性内脏痛大鼠离体脑片高频刺激诱导的长时程增强可使海马Glu R2表达水平增高,而对Glu R1表达量无明显影响。结论新生期母婴分离应激可导致大鼠海马AMPARs的Glu R2亚型上调及CA1区长时程增强易化,从而导致大鼠成年后内脏痛敏。
[Abstract]:Objective to explore the hippocampal alpha amino -3- hydroxy -5- methyl 4- ISO oxazole propionic acid receptor (a-amino-3-hydroxy-5-methyl-4-isoxazole-propionate receptor, AMPARs) in irritable bowel syndrome (Irritable bowel, syndrome, IBS) the role and mechanism of central sensitization of chronic functional visceral pain in rats, in order to reveal IBS chronic functional visceral pain pathogenesis, provide a new IBS thought for chronic functional visceral pain clinical prevention and drug development. The first 3~21 days after birth of neonatal SD rats, fixed time every day to give 3 hours of maternal separation of psychological stress, construction of IBS chronic visceral pain model, the rats in control group except no maternal separation, other treatments were consistent with the model group rats. Adult (8 weeks), abdominal distension method of external oblique discharge reaction by detecting 40 and 60 mm Hg colorectal evaluation model of success, hyperalgesia were selected by three-dimensional experiments. Location of catheter, trace bilateral hippocampal injection of different doses of AMPARs inhibitor CNQX (10,20,40 nmol, each side of 2 L), were observed and compared before and after administration of different pressure abdominal external oblique discharge reaction and duration of action. By detecting the Western blot method to compare normal and AMPARs in hippocampus of rats with IBS subtype (Glu R1, Glu the expression level of R2); application of in vitro brain field potential recording method to observe the IBS in rat hippocampal CA1 long-term potentiation (long-term, potential, LTP) is easy, and the high frequency stimulation after 60min from hippocampal slices by Western blot to detect the expression of Glu Glu R1, R2. Results IBS chronic function visceral pain in rats with visceral hypersensitivity reaction than normal rats increased markedly. The bilateral hippocampal microinjection of AMPARs inhibitor CNQX could dose dependently inhibit the rat visceral hypersensitivity reaction inhibition after administration of 30min is the highest, lasts about 90min. Compared with control rats, IBS chronic functional visceral pain in rats of AMPARs subtype Glu R2 expression was significantly increased, but no significant difference between the expression level of Glu R1. The IBS of chronic functional visceral pain rats induced by high frequency stimulation in hippocampal LTP increased compared with normal rats. Brain slices induced by high frequency stimulation in the normal and IBS chronic functional visceral pain rats potentiation of hippocampal Glu R2 expression level can be increased, and the Glu R1 expression had no obvious effect. Conclusion the neonatal maternal separation stress can induce AMPARs rat hippocampal Glu subtype R2 and upregulation of CA1 region process to strengthen, resulting in adult rats with visceral hypersensitivity.

【学位授予单位】：福建医科大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R574.4

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