Distribution of nerves containing vasoactive intestinal polypeptide-like immunoreactivity in rats with congenital aganglionosis of the colon.

The distribution of nerves containing vasoactive intestinal polypeptide-like immunoreactivity was examined immunohistochemically in whole-mount specimens of the colons of mutant rats, which completely lacked intramural nerve cells in the colon, and of their normal littermates. In the aganglionic colon, greatly diminished numbers of vasoactive intestinal polypeptide-like immunoreactive nerve fibers were found in the circular muscle layer, lamina propria of the mucosa, and in the submucosa. In the intermuscular space of the aganglionic colon, unlike the pattern of the normal Auerbach's plexus, vasoactive intestinal polypeptide-like immunoreactive nerve fibers were arranged in an irregular, coarse network. These findings suggest the existence of extrinsic nerves containing vasoactive intestinal polypeptide in the aganglionic colon of the hereditary aganglionic rat.