neuropeptide-y and Hirschsprung-Disease

Despite technically satisfactory operations, at least 20% of children with Hirschsprung's disease have an unsatisfactory postoperative result. A possible explanation for their symptoms is the retention of ganglionic intestine which has demonstrable abnormalities of the enteric nervous system. The distribution of intestinal neural proteins and peptides in resected colons from patients with Hirschsprung's disease (n = 10) was compared with that in normal controls (n = 5). Immunocytochemistry was performed using antisera against general markers of the enteric nervous system (PGP 9.5, NSE, NFILs, and S-100 protein) and colonic neuropeptides (VIP, GAL, SP, NPY, CGRP, and Met-ENK). The distribution and density of peptide-containing nerve fibers varied greatly from one patient to another and no consistent pattern of neural disturbances could be discerned in aganglionic colon. At the proximal limit of resection, abnormalities of enteric innervation were detected in 8 of 10 studied specimens. Although ganglion cells staining positively for general neuronal markers were present in all cases, normal populations of neural cell bodies immunoreactive for neuropeptides could be found in only 2 specimens. Enlarged submucosal nerve trunks found in the most proximal area of most specimens, displayed immunoreactivity for general nerve markers and VIP, GAL, NPY, and CGRP. The widely practised conventional histopathological assessment of the proximal limit of colonic neural abnormalities may be inadequate.

Topics: Calcitonin Gene-Related Peptide; Child; Child, Preschool; Colon; Colostomy; Enkephalin, Methionine; Female; Galanin; Hirschsprung Disease; Humans; Immunoenzyme Techniques; Infant; Male; Nerve Fibers; Neuropeptide Y; Neuropeptides; Peptides; Submucous Plexus; Substance P; Vasoactive Intestinal Peptide

In Hirschsprung's disease, the aganglionic bowel is characterized by an absence of ganglion cells and an increased number of adrenergic and presumed cholinergic nerve fibers. In addition, a severe derangement of peptide-containing nerve fibers is encountered including a hyperinnervation of neuropeptide Y (NPY)-containing fibers. Using immunochemical and immunocytochemical methods, we examined the nature of the NPY-containing nerve fibers contributing to the hyperinnervation. The concentration of NPY was markedly increased in the aganglionic segment. Coexistence of NPY, vasoactive intestinal peptide (VIP), and the adrenergic enzyme tyrosine hydroxylase (TH) showed small populations of nerve fibers containing NPY/TH, NPY/VIP, or TH alone in ganglionic intestine. Numerous nerve fibers stored VIP but lacked NPY. These fibers did not contain TH, indicating that all VIP-containing fibers are nonadrenergic. In the aganglionic intestine there was a marked increase in the number of nerve fibers storing NPY/TH and NPY/VIP, whereas the fibers storing VIP alone were reduced in number. A small number of nerve fibers storing NPY alone occurred in the hypertrophic nerve bundles. NPY/VIP-containing nerve fibers were particularly numerous in the mucosa in aganglionic intestine, which may be of interest in the diagnosis of Hirschsprung's disease allowing the use of mucosal biopsy specimens. Thus, the proliferating NPY-containing nerve fibers in the aganglionic intestine seem to comprise three different populations, one adrenergic and two nonadrenergic, one of which contains in addition VIP.

Topics: Adrenergic Fibers; Child; Child, Preschool; Hirschsprung Disease; Humans; Immunohistochemistry; Infant; Intestine, Large; Nerve Fibers; Neuropeptide Y; Tyrosine 3-Monooxygenase; Vasoactive Intestinal Peptide

The localisation and distribution of neuropeptide Y (NPY)-like immunoreactivity were studied by use of immunohistochemical methods in gut tissues from 19 patients with Hirschsprung's disease, including 4 cases of long segment aganglionosis. In the normoganglionic segment, immunoreactive cell bodies and nonvaricose processes were seen within both myenteric and submucous plexuses. A scarce supply of varicose fibres was found in the lamina propria mucosae, muscularis mucosae and longitudinal muscle layer. NPY fibres were more frequently encountered in the circular muscle layer, although with a weakly immunostaining intensity. In addition, blood vessels in the submucosal connective tissue were surrounded by a typical plexus of varicose, NPY-positive fibres. Immunoreactive endocrine cells could be detected in the colonic epithelium. In the aganglionic segment, numerous nerve fasciculi comprising a small to moderate number of NPY fibres with varicosities were observed throughout the entire layer of the colonic wall. A few varicose, NPY-positive fibres were also contained in the relatively large, hypertrophic nerve fasciculi located in the intermuscular zone and submucosal connective tissue. NPY-immunoreactive fasciculi were more densely distributed in the distal aganglionic segment than in the proximal aganglionic one. On the other hand, the distribution of NPY-positive fibres in long segment aganglionosis was quite different from that in short segment type; in cases of long segment type, no immunoreactive nerve fibres were detected within the circular muscle layer of the proximal aganglionic segment near the oligoganglionic segment and only a few fibres were observed within the hypertrophic nerve bundle of the intermuscular zone.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Child; Child, Preschool; Colon; Ganglia; Hirschsprung Disease; Humans; Immunoenzyme Techniques; Infant; Nerve Fibers; Neuropeptide Y

The aganglionic intestinal segment in Hirschsprung's disease is known to contain a reduced number of nerve fibers storing vasoactive intestinal peptide (VIP), substance P (SP), enkephalin, and gastrin-releasing peptide (GRP). In this study, nerves containing three newly described neuropeptides: neuropeptide Y (NPY), calcitonin gene-related peptide (CGRP), and galanin were examined using immunocytochemistry. Nerve fibers displaying NPY immunoreactivity were found to be more frequent in the aganglionic than in nonafflicted ganglionic intestine. Nerve fibers storing CGRP and galanin on the other hand were roughly equally frequent but the distribution pattern differed in that the bulk of fibers in the aganglionic intestine was localized to large nerve trunks not seen in the ganglionic segment. The functional significance of these changes has yet to be defined.

Topics: Calcitonin; Calcitonin Gene-Related Peptide; Galanin; Ganglia; Hirschsprung Disease; Humans; Immunohistochemistry; Neuropeptide Y; Neuropeptides; Peptides

A radioimmunoassay for measurement of immunoreactive neuropeptide Y has been developed using antiserum from a rabbit (221) immunized with porcine neuropeptide Y. Antibody 221 has been characterized for both sensitivity and specificity. To determine the distribution of neuropeptide Y in the human gastrointestinal tract, fresh tissue specimens were separated by microdissection into the muscularis externa and the mucosa-submucosa. To examine the origin of neuropeptide Y in human colon, specimens of aganglionic and ganglionic colon were obtained from patients with Hirschsprung's disease. Immunoreactive neuropeptide Y in human gut was present in highest concentrations in the muscularis externa of the stomach and in lowest concentrations in the muscularis externa of the ileum and descending colon. Neuropeptide Y in the stomach was present in higher concentrations in the muscularis externa than in the mucosa-submucosa, but in the descending colon there were lower concentrations of neuropeptide Y in the muscularis externa than in the mucosa-submucosa. In Hirschsprung's disease, concentrations of neuropeptide Y were increased in aganglionic colon in both the muscularis externa and the mucosa-submucosa, compared to corresponding layers from proximal ganglionic colon. Extracts of the gastric muscularis externa and the colonic mucosa-submucosa were separated by C18 reverse-phase high-performance liquid chromatography. One major immunoreactive species was identified by radioimmunoassay which eluted in a position similar to synthetic human neuropeptide Y. These results demonstrated both regional and layer differences in concentrations of neuropeptide Y in human gut. Increased concentrations of neuropeptide Y in aganglionic colon from Hirschsprung's disease most likely result from enlargement of neuropeptide Y-containing extrinsic nerve fibers in both the mucosa-submucosa and the muscularis externa.

Topics: Animals; Antibody Formation; Antibody Specificity; Chromatography, High Pressure Liquid; Digestive System; Hirschsprung Disease; Humans; Iodine Radioisotopes; Neuropeptide Y; Rabbits; Radioimmunoassay; Specimen Handling

The pathophysiology of Hirschsprung's disease has not been fully elucidated but is known to have a neurogenic basis. In recent years, new neural proteins and peptides have been discovered and our aim in this study was to use immunocytochemistry to investigate their involvement in the neuronal abnormalities associated with this condition. Large bowel samples from 9 children undergoing surgery for Hirschsprung's disease were compared with those taken from 8 children with other gastrointestinal diseases but no aganglionosis. Immunocytochemistry was carried out using antibodies to a wide range of neuron specific proteins and peptides. Examination of sections immunostained for the general neuronal markers, protein gene product 9.5, neuron specific enolase and neurofilament triplet proteins, allowed rapid identification of aganglionic segments. Nerves containing vasoactive intestinal polypeptide/peptide histidine methionine (VIP/PHM), galanin, substance P, somatostatin, met-enkephalin or calcitonin gene-related peptide (CGRP) showed a marked reduction in all layers of the aganglionic bowel. However, scattered VIP/PHM immunoreactive fibres were also found in the hypertrophied nerve bundles. In contrast with these reduced peptide-containing nerves, fibres displaying NPY immunoreactivity showed a marked increase in all aganglionic segments, particularly in the circular muscle where few are found normally. Our findings shed further light on the neurobiology of aganglionic bowel and suggest that immunostaining of neural proteins and the peptide NPY can aid rapid histopathological diagnosis of congenital aganglionosis.

Topics: Child, Preschool; Female; Ganglia; Hirschsprung Disease; Histocytochemistry; Humans; Immunochemistry; Infant; Intestines; Male; Nervous System; Nervous System Malformations; Neuropeptide Y