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http://crossmark.crossref.org/dialog/?doi=10.1007/s00441-016-2561-0&domain=pdf
Web End = http://crossmark.crossref.org/dialog/?doi=10.1007/s00441-016-2561-0&domain=pdf
Web End = Cell Tissue Res (2017) 368:277286
DOI 10.1007/s00441-016-2561-0
REGULAR ARTICLE
Glucagon-like peptide-1 is co-localized with neurotensin in the chicken ileum
Kei Nishimura1 & Kohzy Hiramatsu2 & Takafumi Watanabe2 & Kazumi Kita3
Received: 21 July 2016 /Accepted: 14 December 2016 /Published online: 20 January 2017 # Springer-Verlag Berlin Heidelberg 2017
Abstract Glucagon-like peptide (GLP)-1 and neurotensin (NT) are distributed throughout the chicken ileum. Here, we attempt to determine if GLP-1 and NT co-localize in the chicken ileum by using immunofluorescence, immunocyto-chemistry and in situ hybridization techniques. Three types of enteroendocrine cells, GLP-1+/NT+, GLP-1+/NT and GLP-1/NT+ cells, were detected in the mucosal epithelium by the double immunofluorescence method. The ratio of GLP-1+/NT+ cells at the crypts in the distal ileum was significantly higher than that in the proximal ileum. The ratios of the three cell types were similar along the cryptvillous axis in the proximal ileum but the percentage of GLP-1+/NT+ cells significantly decreased at the middle part of villi relative to crypts and the bottom part of villi in the distal ileum. Enteroendocrine cells that were immunoreactive to both GLP-1 and NT peptides and showed both proglucagon and NT precursor mRNA signals were found in the crypts of the distal ileum but not in the villous epithelium. The results from performing an immunocytochemical method with colloidal gold indicated that the GLP-1 content within GLP-1+/NT+ cell secretory granules decreased stepwise from the crypt to the middle part of the villus but the NT content in these granules
increased in this direction. These findings reveal that the cells producing both GLP-1 and NT are mainly localized in the crypts of the chicken ileum but these endocrine cells specialize in NT-producing cells at the villous epithelium of the distal ileum.
Keywords Chicken . Co-localization . Glucagon-like peptide-1 . Ileum . Neurotensin
Introduction
Various kinds of enteroendocrine cells have been identified in the mucosal epithelium of both the mammalian and avian alimentary tracts by using immunohistochemical staining and ultrastructural observation (Buchan and Polack 1980; Fujita and Kobayashi 1977; Larsson 1979; Rawdon and Andrew 1999). These cell types have been named according to their secretory products and the morphology of their secre-tory granules. Glucagon-like peptide (GLP)-1 and neurotensin (NT) are major intestinal hormones and...