【作者】 杨烨；

【导师】 王宝西；

【作者基本信息】 第四军医大学 ， 内科学， 2008， 硕士

【摘要】 实验背景:先天性巨结肠(Hirschsprung’s disease,HD)是以结肠远端或直肠内缺失神经节细胞为特征的胃肠动力性疾病,其病变肠段缺乏推进式运动,从而引起梗阻症状,是新生儿期低位肠梗阻常见原因之一。病因尚未阐明,目前大多认为系遗传及环境多种因素综合作用、共同调控的结果[1]。Cajal间质细胞(interstitial cells of Cajal,ICC)广泛分布于消化道,是胃肠慢波活动的起搏细胞及其基本电节律的主要传播细胞,并参与胃肠道神经信息的传递[2]。近年研究表明,ICC与众多胃肠道疾病关系密切,其分布异常、数目减少可能是这些疾病发病的重要病理生理机制之一。缝隙连接(gap junction,GJ)是相邻两个细胞之间的连接通道排列而成的一种特殊膜结构,相邻细胞通过缝隙连接进行信息、能量和物质交换,参与细胞间物质、电信号的传递。其中连接蛋白43(Connexin43,Cx43)是人类主要细胞缝隙连接蛋白,其表达异常与多种疾病发生有关[3]。实验目的观察缝隙连接蛋白43(Connexin 43,Cx43)及Cajal间质细胞(interstitial cells of Cajal,ICC)在先天性巨结肠(Hirschsprung’s Disease,HD)肠壁中的分布,探讨Cx43和ICC与先天性巨结肠症发病的关系。实验方法运用免疫组织化学方法观察42例经病理诊断为先天性巨结肠的肠壁标本内各层之间Cx43蛋白和ICC的分布情况,其中男33例,女9例(年龄2月—10岁),实验标本全部为散发病例,全部取材经组织病理学检测符合HD诊断,包括常见型30例,短段型12例,并取5例肠套叠患儿(30天—8岁,男4例,女1例)作为对照组。实验结果HD狭窄段(无神经节细胞肠段)肠壁肌层内Cx43和ICC表达缺失,各层中几乎未见Cx43表达和ICC分布,与HD扩张段(有神经节细胞肠段)及正常对照组之间的差异有统计学意义(P<0.01)。HD移行段肠壁Cx43和ICC有中等强度表达,与扩张段、狭窄段之间有明显差异(P<0.01)。HD扩张段肠壁Cx43和ICC呈强阳性分布,粘膜下层和纵肌层未见或少见Cx43表达。HD扩张段和正常对照组肠壁内Cx43和ICC表达无显著性差异(P>0.05)。结论Cx43表达缺失或减少、缝隙连接结构的破坏及ICC结构、分布异常,导致细胞间物质、电信号的传递障碍,可能是先天性巨结肠发病的原因之一。更多还原

【Abstract】 Background and ObjectiveHirschsprung’s disease is a gastrointestinal disease,which is pathologically characterized as the de ficiency of ganglion cells in colon or intestinum rectum. The affection intestines are short of motion and then cause obstruction. HD is a common cause of a disease low-set bowel obstruction in neonatal period.Its etiopathogenisis has not been elucidated yet.Most researchers presume it as a result of heredity and envirment.Interstitial cells of Cajal (ICC) are widely distributed throughout the gastrointestinal tract, which are believed to have a crucial role in gastrointestinal tissues by generating and propagating electrical slow waves to gastrointestinal muscles and/or mediating signals from the enteric nervous system. Recent studies have indicated that the abnormal distribution, the loss or decrease of ICC and the changes of their ultrastructure might play an important role in several disorders of human gastrointestinal motility. Recent studies have indicated that the loss or decrease of ICC and the changes of their ultrastructure might influence the neurotransmission and the function of smooth mucle cell (SMC), and resulted in the dysfunction of human gastrointestinal motility.Gap junction(GJ) is a special membrane structure between two cells,which is arranged by connexins. GJ transmit the intercellular substances and the electrical signals,of which Connexin43 is main of human.The loss or decrease of Cx43 may result in multiple diseases.ObjectiveTo investigate the distribution of Connexin 43(Cx43) and interstitial cells of Cajal (ICC)in Hirschsprung’s disease (HD)bowels and to explore its role in the pathogenesis of HD.Methods42 cases (male 33,female 9)aging from 2 month to 10 years of HD were included in this study using immunohistochemistry method.All cases were sporadic,Of which, common type was in 30 case,short segment type was in 12 case.ONE with Ileal atresia.All cases were diagnosed as HD using histopathological method. The other 5 tissues from patiets(aging from 1 month to 8 years, male 4,female1)with intussusception were used as controls.ResultsThere was no immunoreactivity of Cx43 and ICC in the muscle layers of aganglionic segment in HD,which had significant difference of Cx43 and ICC expressions in ganglionic segment of HD and normal bowels . Moderate immunostainning of Cx43 and ICC were observed at the migratory segment from patients with HD,which had significant difference of Cx43 expression in ganglionic and aganglionic segment of HD.Moderate to strong immunostainning of Cx43 and ICC was observed at the circular muscle and the region between the circular and longitudinal layer in ganglionic segment from patients with HD and in normal bowels.There was no significant difference of Cx43 and ICC expression in ganglionic segment of HD and normal bowels. ConclusionThe lack expression of Cx43 and ICC in the aganglionic bowel of HD and the destruction of the gap junctionin dicate that the impaired intercellular substance exchange .Intercellular communication between cells might partly be responsible for the motility dysfunction in HD.更多还原