title: Histological analysis of glucagon-like peptide-1 receptor expression in chicken pancreas.
abstract: Glucagon-like peptide-1 (GLP-1) released from intestinal L cells in response to nutrient ingestion inhibits both gastrointestinal emptying and gastric acid secretion and promotes satiety. The main biological effect of GLP-1 is the stimulation of insulin secretion (thereby fulfilling the criterion for an incretin hormone) in order to reduce blood glucose levels in mammalian species. Chicken GLP-1 receptor (cGLP-1R) has also been identified in various tissues by gene expression analysis. Although certain effects of GLP-1 in mammals and birds are consistent, e.g., inhibition of food intake, whether GLP-1 has the same insulinotropic activity in chickens as in mammals is debated. Moreover, the expression of cGLP-1R in chicken pancreatic B cells has not been reported. The localization of cGLP-1R and its mRNA in pancreatic islets is studied by triple-immunofluorescence microscopy and in situ hybridization. Triple-immunofluorescence microscopy with antisera against cGLP-1R, somatostatin and insulin or glucagon revealed that cGLP-1R protein was exclusively localized in D cells producing somatostatin in chicken pancreatic islets. The D cells were localized in peripheral areas of the pancreatic islets and cGLP-1R mRNA was detected in the same areas, indicating that cGLP-1R mRNA was also expressed in D cells. This is the first report to demonstrate that cGLP-1R is expressed by D cells, not B cells as in mammals. Our study suggests that chicken GLP-1 performs its insulinotropic activity by a different mode of action from that of the mammalian hormone.
authors.affiliation: Laboratory of Animal Functional Anatomy (LAFA), Department of Food Production Science, Faculty of Agriculture, Shinshu University, 8304 Minamiminowa-mura, Nagano, 399-4598, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Watanabe
authors.forename: Kei
authors.initials: K
authors.lastname: Nishimura
authors.forename: Yoshinao Z
authors.initials: YZ
authors.lastname: Hosaka
authors.forename: Takeshi
authors.initials: T
authors.lastname: Shimosato
authors.forename: Shinichi
authors.initials: S
authors.lastname: Yonekura
authors.forename: Daisuke
authors.initials: D
authors.lastname: Suzuki
authors.forename: Chihiro
authors.initials: C
authors.lastname: Takemoto
authors.forename: Mohammad Moniruzzaman
authors.initials: MM
authors.lastname: Monir
authors.forename: Kohzy
authors.initials: K
authors.lastname: Hiramatsu
mesh_terms: D000818:Animals; D002645:Chickens; D004195:Disease Models, Animal; D000067757:Glucagon-Like Peptide-1 Receptor; D007150:Immunohistochemistry; D007515:Islets of Langerhans / Q000378:metabolism*; D008297:Male; D010179:Pancreas / Q000378:metabolism*; D018027:Receptors, Glucagon / Q000378:metabolism*; D013004:Somatostatin / Q000378:metabolism*
chemical_list: D000067757:Glucagon-Like Peptide-1 Receptor; D018027:Receptors, Glucagon; D013004:Somatostatin