title: Glucagon-like peptide-1 is co-localized with neurotensin in the chicken ileum.
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, immunocytochemistry 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 crypt-villous 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.
authors.affiliation: Department of Bioscience and Food Production Science, Interdisciplinary Graduate School of Science and Technology, Shinshu University, Minami-minowa 8304, Kami-ina, Nagano, 399-4598, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Nishimura
authors.affiliation: Faculty of Agriculture, Shinshu University, Minami-minowa 8304, Kami-ina, Nagano, 399-4598, Japan. seitaik@shinshu-u.ac.jp.
authors.forename: Kohzy
authors.initials: K
authors.lastname: Hiramatsu
authors.affiliation: Faculty of Agriculture, Shinshu University, Minami-minowa 8304, Kami-ina, Nagano, 399-4598, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: Faculty of Agriculture, Iwate University, Ueda, Morioka, Iwate, 020-0066, Japan.
authors.forename: Kazumi
authors.initials: K
authors.lastname: Kita
mesh_terms: D000818:Animals; D000918:Antibody Specificity; D002645:Chickens / Q000378:metabolism*; D019858:Enteroendocrine Cells / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D052216:Glucagon-Like Peptide 1 / Q000235:genetics / Q000378:metabolism*; D007082:Ileum / Q000166:cytology / Q000378:metabolism*; D017403:In Situ Hybridization; D008297:Male; D009496:Neurotensin / Q000235:genetics / Q000378:metabolism*; D012322:RNA Precursors / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D022142:Secretory Vesicles / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D012322:RNA Precursors; D012333:RNA, Messenger; D009496:Neurotensin; D052216:Glucagon-Like Peptide 1
keywords: Chicken; Co-localization; Glucagon-like peptide-1; Ileum; Neurotensin