神经生长因子及其受体在肛门直肠畸形动物模型直肠末端的表达及意义

目的 观察肛门直肠畸形(ARM)动物模型直肠末端组织中神经生长因子(NGF)及其受体(NGFR)的表达,探讨ARM排便功能障碍的机制.方法 应用免疫组织化学和RT-PCR检测正常与肛门直肠畸形动物胎鼠直肠末端组织中NGF及其高亲和力受体(TrkA)、低亲和力受体(p75NTR)的表达.结果 NGF、TrkA、p75NTR在正常胎鼠直肠末端肠黏膜皱襞及肌层细胞质及细胞核中有大量表达,其平均光密度(IOD值)分别为731.749±232.177,262.815±101.722,134.674±67.127,而在肛门直肠畸形直肠末端表达较少,其平均光密度(IOD值)分别为17.973±74.945,33.145±11.128,113.010±36.468,两组比较,差异均有统计学意义(P＜0.05)；TrkAmRNA、P75NTRmRNA在正常胎鼠直肠末端组织中的相对表达量分别为162.221±104.675,129.778±51.967,在肛门直肠畸形胎鼠中的相对表达量分别为78.973±33.425,87.145±25.812,两组比较,差异有统计学意义(P＜0.05).结论 NGF及其受体TrkA、p75NTR在ARM动物模型直肠末端的表达异常可能是导致其排便功能障碍的原因之一.

The expression of NGF and NGFR in distal rectum in fetal rats with anorectal malformations

Objective To study the expression of nerve growth factor (NGF) and nerve growth factor receptor (NGFR) in distal rectum in fetal rats with anorectal malformations.Methods The intragastric administration of ethylenethiourea was performed in fetal rats to create anorectal malformation model.The expression level of NGF,TrkA and p75NTR of distal rectum tissues in fetal rats were studied by using immunohistochemistry and RT-PCR.Results In normal control group,the average IOD value of NGF and TrkA,as well as p75NTR were respectively 731.749 ± 232.177,262.815 ± 101.722 and 134.674 ± 67.127,while in induced ARM group they were 17.973 ± 74.945、33.145 ± 11.128、113.010 ± 36.468 respectively.There are significant differences between both groups(P＜0.05).In term of mRNA relative expression of TrkA and P75NTR,they also presented remarkably statistical differences via comparison (Normal control group:162.221 ± 104.675 and 129.778 ± 51.967; while the induced ARM group:78.973 ± 33.425 and 87.145 ± 25.812) (P＜ 0.05).Conclusions The abnormal expression of NGF and NGFR,might be one of the pathogenesis that plays important role in defecation functional perturbation in fetal ARM rats.