食管滴酸刺激诱导内脏致敏大鼠岛叶基因表达谱的改变

Gene expression prof ile changes in the insular lobe of visceral sensitive rats following esophageal acid perfusion

目的:观察酸刺激模式下经腹腔卵清蛋白(OVA)致敏大鼠岛叶中基因谱的改变.方法:SD大鼠20只分为3组:A组于实验前1d腹腔注射OVA与氢氧化铝混合液[OVA100mg,Al(OH)3200mg]1.5mL致敏;B组于实验前1d腹腔注射生理盐水1.5mL作假手术对照;C组不予处理作空白对照.实验第14天,对A、B、C组动物分别进行食管酸灌注,使用0.1mol/L盐酸滴注,滴注液保持37℃,速度10mL/h,共50min.通过脑定位仪定位岛叶并取材保存,对标本进行RNA抽提和纯化后,采用基因芯片进行寡核苷酸芯片杂交,并对芯片差异基因进行数据分析.结果:在食管滴酸灌注致敏SD大鼠后,31099个待测基因中,3组间显著差异表达基因389条(1.25%),其中已知功能基因158条,未知功能基因231条,有显著性功能的基因有21条(4.88%).这些基因主要涉及到初级代谢产物、转移酶活性、ATP结合物、阳离子结合物,细胞定位,阳离子转运等.下调的基因中包括了调控与内脏感觉相关的5-HT1B受体基因.结论:岛叶皮层中枢可能存在有通过中枢下行抑制的减弱致内脏高敏感的中枢机制,HTR1B基因的下调可能在调控食管内脏感觉中发挥着重要的作用.

AIM： To investigate the changes of gene expression profile in the insular lobe of enterocoelia OVA sensitized rat after esophageal acid perfusion using gene chips. METHODS： Twenty male Sprague-Dawley （SD） rats were randomly divided into 3 groups. The rats in group A were sensitized by abdominal injection of 1.5 mL mixed liquor [OVA 100 mg, AI（OH）3 200 rag] in the beginning of the experiment. The rats in group B received abdominal injection of 1.5 mL normal sodium in the beginning of the experiment as sham operation group. The rats in group C were raised without any special interposal as control group. On the 14th day of the experiment, all rats in 3 groups re-ceived esophageal acid perfusion with 0.1 mol/L HC1, the drops was kept at 37℃ and 10 mL/h, the total duration lasted 50 min. According to the brain position indicator, the insular lobe was located and dissected then preserved in liquid nitrogen as samples. After RNA extraction and purification, the samples underwent oligonucleotide Array hybridization using gene clips and analyzed in differentially expressed genes. RESULTS： Among the total 31 099 genes ex- tracted from sensitized rats, there were 389 genes differentially expressed in 3 groups, involving 158 genes with definite functions and 231 genes with undefined functions. There were 21 remarkable function genes （9 up-regulated and 11 down-regulated）. The gene functions referred to primary metabolite, transferase activity, ATP conjugate, positive ion conjugate, cellular positioning, and positive ionic transportation. The genes in down-regulated expression involved 5-HTIB receptor gene which was related to visceral sensation. CONCLUSION： There should be a certain descending mechanism of visceral hypersensitivity inhibition in insular lobe cortex, and the downregulated expression of HTRIB genes seems to play an important role in the visceral sensation.