Increased tissue concentration of neuropeptide Y in the duodenal mucosa in coeliac disease.

Neuropeptide Y (NPY) is localized to intestinal nerve fibres, of which there are few in normal duodenal mucosa. In the duodenal mucosa of 10 patients with coeliac disease and in a control group of 21 patients with other gastrointestinal symptoms but with normal function of the small intestine we studied the frequency of such fibres by immunohistochemistry and the tissue concentration of NPY by radioimmunoassay. Patients with coeliac disease had an increased number of NPY nerve fibres and significantly elevated tissue concentrations compared with the control group. The eluted fractions obtained by high-pressure liquid chromatography of duodenal extracts showed the same immunoreactive components in the two groups. This study therefore suggested proliferation of the peptide-containing nerve system in coeliac disease. The increased NPY levels in the duodenal mucosa may be of functional significance for the disease symptoms.