title: Increased amounts of a high molecular weight insulin-like growth factor II (IGF-II) peptide and IGF-II messenger ribonucleic acid in pancreatic islets of diabetic Goto-Kakizaki rats.
abstract: Insulin-like growth factor II (IGF-II), a member of the insulin family, regulates cell growth and differentiation. The IGF-II gene is localized close to the insulin gene in man and rat. IGF-II peptide binds weakly to the insulin receptor and exerts insulin-like effects on the blood glucose level. We studied IGF-II in endocrine pancreas in an animal model of noninsulin-dependent diabetes mellitus, the Goto-Kakizaki (GK) rat. At the age of 2 months, these rats have structural islet changes, with fibrosis and irregular configuration, so-called starfish-shaped islets. Immunohistochemical investigation revealed IGF-II immunoreactivity in the beta-cells in both GK and control rats. Pancreatic extraction, followed by size separation using gel chromatography, disclosed a high mol wt form of IGF-II in all animals, and RIA measurements revealed a considerably larger amount of the IGF-II peptide in the 2-and 6-month-old GK rats than in the 1-month GK and control rats. In situ hybridization of 3-month-old GK rats showed increased IGF-II messenger RNA expression in the starfish-shaped islets of GK rats than in the islets with normal structure in both diabetic and control animals. The reason for the increased amount of IGF-II is unclear. As the animals are diabetic before the islet changes occur, it might be a compensatory effect in response to hyperglycemia, but could also be a cause of the islet fibrosis.
authors.affiliation: Department of Tumor Pathology, Karolinska Institute and Hospital, Stockholm, Sweden. andersh@path.ks.se
authors.forename: A
authors.initials: A
authors.lastname: Höög
authors.forename: A C
authors.initials: AC
authors.lastname: Sandberg-Nordqvist
authors.forename: S M
authors.initials: SM
authors.lastname: Abdel-Halim
authors.forename: C
authors.initials: C
authors.lastname: Carlsson-Skwirut
authors.forename: A
authors.initials: A
authors.lastname: Guenifi
authors.forename: M
authors.initials: M
authors.lastname: Tally
authors.forename: C G
authors.initials: CG
authors.lastname: Ostenson
authors.forename: S
authors.initials: S
authors.lastname: Falkmer
authors.forename: V R
authors.initials: VR
authors.lastname: Sara
authors.forename: S
authors.initials: S
authors.lastname: Efendić
authors.forename: M
authors.initials: M
authors.lastname: Schalling
authors.forename: L
authors.initials: L
authors.lastname: Grimelius
mesh_terms: D000818:Animals; D001835:Body Weight; D003920:Diabetes Mellitus / Q000378:metabolism* / Q000473:pathology; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism; D004195:Disease Models, Animal; D005951:Glucose Tolerance Test; D017403:In Situ Hybridization; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000235:genetics; D018974:Insulin-Like Growth Factor Binding Protein 4 / Q000235:genetics; D007335:Insulin-Like Growth Factor II / Q000235:genetics / Q000378:metabolism*; D007515:Islets of Langerhans / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008854:Microscopy, Electron; D008970:Molecular Weight; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D017208:Rats, Wistar; D011972:Receptor, Insulin / Q000378:metabolism
chemical_list: D018970:Insulin-Like Growth Factor Binding Protein 1; D018974:Insulin-Like Growth Factor Binding Protein 4; D012333:RNA, Messenger; D007335:Insulin-Like Growth Factor II; D011972:Receptor, Insulin