title: Immunocytochemical localization of secretogranin III in the endocrine pancreas of male rats.
abstract: Secretogranin III (SgIII), a member of the granin protein family, is expressed specifically in neuronal and endocrine cells. To examine the precise localization of SgIII in the endocrine pancreas, pancreatic tissues of rats were analyzed immunocytochemically with a polyclonal anti-serum raised against rat SgIII. By light microscopy of semithin sections, the immunoreactivity for SgIII was readily detected in pancreatic A- and B-cells, faintly so in D-cells, and not at all in the exocrine pancreas. By immunoelectron microscopy, immunogold particles indicative of SgIII were observed in the peripheral regions of secretory granules, and universally in the pancreatic endocrine cells. Morphometrical analyses indicated that SgIII is most preferentially localized in the periphery of the secretory granule among granins. These findings suggest that SgIII is closely associated with the secretory granule membrane, serving to anchor the aggregates of other soluble constituents to the membrane.
authors.affiliation: Department of Anatomy II, Asahikawa Medical College, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Sakai
authors.forename: Masahiro
authors.initials: M
authors.lastname: Hosaka
authors.forename: Akihiro
authors.initials: A
authors.lastname: Yoshinaga
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Hira
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Harumi
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D000906:Antibodies; D002864:Chromogranins; D007150:Immunohistochemistry; D007515:Islets of Langerhans / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D011506:Proteins / Q000276:immunology / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D022142:Secretory Vesicles / Q000378:metabolism*; D019864:Somatostatin-Secreting Cells / Q000378:metabolism
chemical_list: D000906:Antibodies; D002864:Chromogranins; D008565:Membrane Proteins; D011506:Proteins