IMPAIRED EXPRESSION OF NEURAL CELL-ADHESION MOLECULE L1 IN THE EXTRINSIC NERVE-FIBERS IN HIRSCHSPRUNGS-DISEASE

Immunohistochemical studies on the ganglionic and aganglionic segment in Hirschsprung's disease (HD) were carried out using antibodies again st three neural membrane proteins, Thy-1, Integrin alpha 5, and ii. En teric neural elements were immunostained with antibodies against neuro filament, which is the neuronal cytoskeletal protein. In ganglionic se gments, neurofilament-immunoreactivity was detected in neuronal cell b odies and fine nerve fibers of the myenteric and submucosal plexuses. All of these neural elements were immunopositive for Thy-1, integrin a lpha 5, and ii. In aganglionic segments, no intrinsic neurons were det ected, and instead, hypertrophied nerve bundles were observed in inter muscular space, in submucosa, and in circular muscle layer by immunoch emistry for neurofilament. These hypertrophied nerve bundles were immu nopositive with anti-Thy-1 and anti-integrin alpha 5 antibodies. Howev er, they were not immunostained with anti-ii in all five cases. These findings indicate that the expression of ii molecule, which plays an i mportant role in cell adhesion, neural cell migration, and neurite out growth, is impaired in the extrinsic nerve fibers in aganglionic colon , And this may perturb neural crest migration and adequate neurite out growth, with resulting aganglionic segment and abnormal nerve bundles of extrinsic fibers in HD. Copyright (C) 1997 by W.B. Saunders Company .