NPY immunoreactivity in endocrine cells of duck pancreas: An ontogenetic study

In the literature, neuropeptide Y (NPY) has been described in the brain and peripheral nerves. More recently, it has also been detected in endocrine c ells of hamster, embryonic mouse, and rat pancreas. However, the presence o f NPY in avian embryos and the possible colocalization of this peptide with the of her pancreatic hormones have not been reported previously. In this study, NPY presence was studied by immunocytochemical methods in the endocr ine pancreas of domestic duck during pre- and postnatal development. NPY im munoreactivity (IR) was detected in embryos and adult animals. Around hatch ing the intensity of IR in endocrine cells decreased. Double immunohistoche mical staining revealed that: 1) NPY-IR is extensively colocalized in small and mixed islets with insulin-IR both in embryos and in adults; and 2) in early embryos NPY-IR occasionally colocalized with glucagon and somatostati n. In early embryos, the colocalization of NPY-IR with several pancreatic h ormones could be related to the presence of multihormonal progenitor cells. The close relation between insulin and NPY, both in embryos and adults, le d us to hypothesize a key role for NPY on insulin cells of duck pancreas. A nat Rec 259:35-40, 2000. (C) 2000 Wiley-Liss, Inc.