Increased expression of muscular neural cell adhesion molecule in congenital aganglionosis

Neural cell adhesion molecule (NCAM) is down regulated during morphogenesis and innervation of cardiac and skeletal muscle. In mature muscle, its reexpression over the entire sarcolemma occurs in response to denervation or paralysis of muscle and in some myopathies. No information is available regarding NCAM expression in human enteric muscle either in health or in disease. Our aim was to test whether NCAM is present in nerves and muscle of normal infant bowel and to determine how its expression is altered in congenital aganglionosis.

Using immunocytochemistry for light microscopy, we compared the pattern of distribution of NCAM in congenitally aganglionic colon with that in colon from age-matched controls.

In normal colon, NCAM immunoreactivity was seen in ganglion cells and nerve fibers throughout the gut wall and, more weakly, on the inner border of the circular muscle. In aganglionic bowel, there was a marked increase in NCAM expression in muscle, particularly that of the muscularis mucosac and characteristic hypertrophied nerve bundles of the intermuscular zone and submucosa displayed immunoreactivity for NCAM.

Abnormal expression of NCAM is, thus, a feature of congenital aganglionosis and is likely to be associated with neuromuscular dysfunction within the affected colon.