Chronological characterization of diabetes development in male Spontaneously Diabetic Torii rats.
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.
Masuyama
Taku
T
Torii Pharmaceutical Co. Ltd., 3-4-1 Nihonbashi-honcho, Chuo-ku, 103-8439, Tokyo, Japan. t.masuyama@tba.t-com.ne.jp
Komeda
Kajuro
K
Hara
Akemi
A
Noda
Mitsuhiko
M
Shinohara
Masami
M
Oikawa
Toshihiro
T
Kanazawa
Yasunori
Y
Taniguchi
Kazuyuki
K
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
D001786:Blood Glucose; D007328:Insulin