title: Chronological characterization of diabetes development in male Spontaneously Diabetic Torii rats.
abstract: To characterize the underlying mechanisms of diabetes development in males of the Spontaneously Diabetic Torii (SDT) rat, a novel spontaneous model for diabetes, we chronologically examined them, focusing on their diabetic features and the pathological changes in the pancreatic islets. Male SDT rats exhibited glucose intolerance with impaired insulin secretion after 14 weeks and developed diabetes with remarkable hyperglycemia and marked hypoinsulinemia after 20 weeks. At prediabetic stage (10-20 weeks), they were normoglycemic, but had significantly lower insulin levels of plasma and pancreas than the normal rats. Their beta-cell volume was already smaller significantly at 10 weeks than that of normal rats. The primary changes of the pancreatic islets were microvascular events such as congestion and hemorrhage at 8-10 weeks. Thereafter, the SDT rat islets were affected with inflammation and progressive fibrosis (at 10-20 weeks), and eventually atrophied with a loss of beta-cells (at 38 weeks). These results indicate that the male SDT rats develop spontaneous diabetes with an absolute decrease in the insulin secretory capacity of the islets.
authors.affiliation: Torii Pharmaceutical Co. Ltd., 3-4-1 Nihonbashi-honcho, Chuo-ku, 103-8439, Tokyo, Japan. t.masuyama@tba.t-com.ne.jp
authors.forename: Taku
authors.initials: T
authors.lastname: Masuyama
authors.forename: Kajuro
authors.initials: K
authors.lastname: Komeda
authors.forename: Akemi
authors.initials: A
authors.lastname: Hara
authors.forename: Mitsuhiko
authors.initials: M
authors.lastname: Noda
authors.forename: Masami
authors.initials: M
authors.lastname: Shinohara
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Oikawa
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Kanazawa
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Taniguchi
mesh_terms: D000818:Animals; D019540:Area Under Curve; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics / Q000473:pathology*; D004195:Disease Models, Animal; D018450:Disease Progression; D005951:Glucose Tolerance Test; D007150:Immunohistochemistry; D015994:Incidence; D007328:Insulin / Q000097:blood; D007515:Islets of Langerhans / Q000473:pathology / Q000648:ultrastructure; D008297:Male; D009929:Organ Size; D010179:Pancreas / Q000473:pathology; D051381:Rats; D011919:Rats, Inbred Strains; D017207:Rats, Sprague-Dawley; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D007328:Insulin