Changes of Glycoconjugates in Hirschsprung's disease

Hirshsprung病已知是由myenteric ganglia缺失引起的。我们试图研究主要由糖缀合物构成的胚胎微环境，它对未分化的神经母细胞迁移和成熟起着重要的作用。采用凝集素染色法观察巨结肠发育过程中及巨结肠内糖缀合物的变化。采用16种不同的凝集素（ConA、RCA-1、WGA、PNA、SBA、UEA-1、DBA、LCA、PHA-L、DSA、GS-1、VVA、MPA、BPA、MAA和PSA），通过光镜和电镜观察了15 ~ 21日龄大鼠结肠远端部分Auerbach神经丛凝集素的结合模式。妊娠第19天时，ConA的结合量随着奥尔巴赫神经丛的分化而增加；妊娠第17天时，DSA、MPA、RCA-1的染色量随着奥尔巴赫神经丛的呈现而增加。电镜下，DSA结合位点主要定位于神经细胞的质膜、高尔基体和核膜。神经细胞突、雪旺细胞及其周围平滑肌细胞的腋膜、质膜均呈阳性。n -聚糖酶消化试验表明，n型寡糖在奥尔巴赫神经丛的发育中起重要作用。在Hirschsprung病中，DSA、RCA-1和WGA在神经节段平滑肌层的染色强于正常神经节段。这一发现提示，在巨结肠病的奥尔巴赫神经丛发育阶段，n -连接寡糖可能出现异常。

Hirshsprung's disease is known to be caused by the absence of myenteric ganglia. We attempted to study the embryonic microenvironment which is mainly constituted by glycoconjugates and play an important role for undifferenciated neuroblasts to migrate and maturate. We applied lectin staining to observe the changes of glyoconjugates in the colon during development and in the colon of Hirschsprung's disease.The lectin binding patterns in Auerbach's plexus of the distal portions of the rat colon from 15- to 21-day-old fetuses, newborns, and adults were examined by light and electron microscopy using sixteen different lectins (ConA, RCA-1, WGA, PNA, SBA, UEA-1, DBA, LCA, PHA-L, DSA, GS-1,VVA, MPA, BPA, MAA and PSA ). ConA was shown to increase in their binding after day 19 of gestation with differenciation of Auerbach's plexus, while DSA, MPA, and RCA-1 increased their staining intensity after day 17 of gestation in accordance with the appearance of Auerbach's Plexus. Under electron microscopy, DSA binding sites were localized mainly in the plasma membrane, Golgi apparatus, and nuclear membrane of nerve cells. Positivities were also observed in the axolemma and in the plasma membrane of nerve cell processus, Schwann cells and their surrounding smooth muscle cells. N-glycanase digestion test suggested that N-liked oligosaccbarides play an important role in the development of the Auerbach's plexus.In Hirschsprung's disease, DSA, RCA-1 and WGA were stained stronger in the smooth muscle layer of the aganglionic segment than in that of the normo-ganglionic segment. This finding suggested that N-linked oligosaccharides may have been abnormal at the developmental stage of Auerbach's plexus in Hirschsprung's disease.