Immunohistochemical localization of neuropeptides in bovine pancreas

The occurrence and density of distribution of nerves and endocrine cells th at are immunoreactive for neuropeptides in the bovine pancreas were studied by immunohistochemistry. The six neuropeptides localized were galanin (GAL ), substance P (SP), methionine-enkephalin (MENK), neuropeptide Y (NPY), ca lcitonin gene-related peptide (CGRP) and vasoactive intestinal polypeptide (VIP). The exocrine pancreas was shown to have an appreciable number of GAL - and SP-immunoreactive nerve fibres but few fibres showing immunoreactivit y for VIP and CGRP. Numerous MENK-, GAL-, SP-, and NPY-immunoreactive nerve fibres were seen in the endocrine portion of the pancreas. Nerve cell bodi es in the intrapancreatic ganglia showed immunoreactivity for all of the ne uropeptides except CGRP. Endocrine cells showing immunoreactivity for GAL a nd SP were observed in the large islets and islets of Langerhans, respectiv ely. The present results indicate a characteristic distribution of neuropep tides in the bovine pancreas, which may regulate both exocrine and endocrin e secretions of pancreas.