Ghrelin在大鼠神经系统中的表达对胃黏膜的保护作用  

Expression of Ghrelin in nervous system and its cytoprotective action in rats

作　　者：徐珞[1] 孙向荣[1] 韩晓华[1] 钟凤[1] Inge Depoortere Theo Peeters 

机构地区：[1]青岛大学医学院,山东省青岛市266021 [2]天主教鲁汶大学

出　　处：《世界华人消化杂志》2006年第8期752-757,共6页World Chinese Journal of Digestology

基　　金：国家自然科学基金资助项目;No.30470642;青岛市科技局资助项目;No.05-1-JC-93

摘　　要：目的:研究大鼠脑、小肠肌间神经丛神经元和血浆内Ghrelin的表达,探讨Ghrelin在水浸加束缚应激性胃溃疡中的作用及机制．方法:选择健康♂Wiater大鼠76只,随机分为 6组:水浸加束缚组(10只);侧脑室注射Ghrelin 组(24只);皮下注射L-NAME+侧脑室注射 Ghrelin组(8只)和相应的3个对照组(正常大鼠组18只,侧脑室注射生理盐水组8只,皮下注射 L-NAME+侧脑室注射生理盐水组8只)．采用放射免疫分析、荧光免疫组化双染和神经生理学等实验方法,观察脑、小肠肌间神经丛和血浆内Ghrelin的表达,探讨Ghrelin对大鼠束缚加水浸诱导的应激性胃溃疡的影响及机制．结果:在正常大鼠小肠肌间神经丛内和原代培养的肠肌间神经丛神经元均可见有Ghrelin 样免疫反应阳性物(Ghrelin-IR)的表达,且 Ghrelin-IR与胆碱乙酰转移酶(CHAT)共同表达于同一神经元内,但Ghrelin-IR不与一氧化碳合酶(NOS)和消化道感觉性神经元内特有的钙结合蛋白(Calbindin,Calb)共存．在大鼠应激性胃溃疡产生的同时,其血浆内Ghrelin- IR的含量明显减少(198．3±29．6 ng/L vs 141．7 ±26．5 ng／L．P=0．026)．而下丘脑、延脑、垂体和肌间神经丛神经元内Ghrelin-IR的含量明显升高(分别为96．2±18．1 pg／mg vs 153．2 ±11．6 pg／mg．P=0．006;89．8±16．5 pg／mg vs 144．4±13．9 pg／mg,P=0．007;108．3± 11．9 pg／mg vs 198．2±23．3 pg／mg,P=0．002; 48．8±12．8 pg／mg vs 86．2±21．5 pg／mg．P= 0．02);侧脑室注射Ghrelin大鼠应激性胃溃疡的产生明显减少,且呈明显的量效依赖关系(溃疡指数:生理盐水,86．7±6．2;50 ng Ghrelin,79．3±10．7 P=2．18;500 ng Ghrelin, 61．3±11．7,P=0．04;5 000 ng Ghrelin,35．6 ±10．8,P=0．005),经sc一氧化氮合酶抑制剂 L-NAME后,Ghrelin的胃黏膜细胞保护作用消失．结论:Ghrelin与ChAT共存表达于肠肌间神经丛胆碱能神经元;应激性胃溃疡发生时,中枢神经系统和血浆内GhrelinAIM： To investigate the expression of Ghrelin in brain, intestinal myenteric plexus and plasma and study its possible cytoprotective effect and mechanism on gastric mucosa against stressinduced ulcers. METHODS： Seventy-six healthy male Wistar rats were divided into 6 groups randomly： coldwater restraint group （n = 10）; intracerebroventricular （icv） injection of Ghrelin group （n = 24）; icy injection of Ghrelin after subcutaneous injection of N^ω-Nitro-L-arginine methylester （L-NAME） group （n = 8） and three matched control groups. The expression of Ghrelin in rat brain, intestinal myenteric plexus and plasma were detected by radio-immunoassay （RIA） and double staining of immunofluorescence and immunohistochemistry. The effect and mechanism of Ghrelin on gastric mucosa against stressinduced ulcer were analyzed using neurophysiologic methods. RESULTS： Ghrelin-positive immunoreaction （1R） was observed in the small intestinal myenteric plexus and primarily cultured myenteric plexus neurons. Ghrelin-IR co-localized with choline acetyl transferase （CHAT）, but not with nitric oxide synthase （NOS） or Calbindin （Calb） in the same myenteric plexus neurons. In comparison with that in its matched control group, the content of Ghrelin-IR in plasma was significantly decreased （198.3 ± 29.6 ng/L vs 141.7 ± 26.5 ng/L, P 〈 0.05）, but increased in hypothalamus, medulla oblongata, pituitary and intestinal myenteric plexus （96.2 ±18.1 pg/mg vs 153.2 ± 11.6 pg/mg, P = 0.006; 89.8 ± 16.5 pg/mg vs 144.4 ± 13.9 pg/mg, P = 0.007; 108.3 ± 11.9 pg/mg vs 198.2 ± 23.3 pg/mg, P = 0.002; 48.8 ± 12.8 pg/mg vs 86.2 ± 21.5 pg/mg, P = 0.02; respectively）. The formation of stress ulcers was markedly inhibited by microinjection of Ghrelin into the ventricle with a dose-dependent manner （ulcer index： normal saline 86.7 ± 6.2; 50 ng Ghrelin 79.3 ± 10.7, P = 2.18; 500 ng Ghrelin： 61.3 ± 11.7, P = 0.04; 5 000 ng Ghrelin： 35.6 ± 10.8, P = 0.005）. However, after a subcuta

关 键 词：GHRELIN 胆碱乙酰转移酶 一氧化氮合酶 应激性胃溃疡 大鼠 

分 类 号：R573[医药卫生—消化系统]