title: Corpuscles of Stannius and stanniocalcin-like immunoreactivity in the white sucker (Catostomus commersoni): evidence for a new cell-type.
abstract: The distribution of stanniocalcin immunoreactivity was examined in the corpuscles of Stannius of the white sucker (Catostomus commersoni) by using a chum salmon stanniocalcin antiserum, Western blotting, and light and electron microscopy. The white sucker possesses at least two stanniocalcin-immunoreactive corpuscles in the most posterior portions of the kidneys. Immunocytochemistry and ultrastructure revealed two cell-types in the corpuscle parenchyma, only one of which was immunoreactive. The nonimmunoreactive cells contained dense-cored vesicles and long processes that extended between the immunoreactive cells and terminated at perivascular spaces. When corpuscle extracts were subjected to electrophoresis and Western blotting, three nonreduced stanniocalcin-like immunoreactive bands (approximately 56, 61, and 64 kDa) were observed. However, in the presence of a reductant, a diffuse band migrating in the range of 28 to 32 kDa was noted. The results of this study on the white sucker demonstrate the presence of a dimeric stanniocalcin-like molecule and present evidence of a previously uncharacterized cell-type in the corpuscles of Stannius.
authors.affiliation: Department of Anatomy and Cell Biology and Division of Life Sciences, University of Toronto at Scarborough, Scarborough, Ontario, Canada M1C 1A4.
authors.forename: L E
authors.initials: LE
authors.lastname: Marra
authors.forename: D G
authors.initials: DG
authors.lastname: Butler
authors.forename: D H
authors.initials: DH
authors.lastname: Zhang
authors.forename: G Y
authors.initials: GY
authors.lastname: Oudit
authors.forename: J H
authors.initials: JH
authors.lastname: Youson
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002118:Calcium / Q000032:analysis / Q000276:immunology; D003531:Cypriniformes / Q000502:physiology*; D006023:Glycoproteins / Q000032:analysis* / Q000276:immunology; D006728:Hormones / Q000032:analysis* / Q000276:immunology; D007668:Kidney / Q000166:cytology; D008854:Microscopy, Electron; D009474:Neurons / Q000737:chemistry* / Q000145:classification* / Q000648:ultrastructure; D009490:Neurosecretory Systems / Q000166:cytology*
chemical_list: D006023:Glycoproteins; D006728:Hormones; C051795:teleocalcin; D002118:Calcium