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Journal of Diabetes Research
Volume 2013, Article ID 976209, 12 pages
http://dx.doi.org/10.1155/2013/976209
Review Article

The Spontaneously Diabetic Torii Rat: An Animal Model of Nonobese Type 2 Diabetes with Severe Diabetic Complications

1Biological/Pharmacological Research Laboratories, Central Pharmaceutical Research Institute, Japan Tobacco Inc., Osaka 569-1125, Japan
2Toxicology Research Laboratories, Central Pharmaceutical Research Institute, Japan Tobacco Inc., Kanagawa 257-0024, Japan
3Division of Cellular and Molecular Medicine, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan
4Division of Molecular and Metabolic Medicine, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan
5Department of Ophthalmology, Saitama Medical Center, Jichi Medical University, Saitama 330-8503, Japan
6Planning and Development Section, CLEA Japan Inc., Tokyo 153-8533, Japan

Received 8 November 2012; Accepted 13 December 2012

Academic Editor: Takahisa Yamada

Copyright © 2013 Tomohiko Sasase et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The Spontaneously Diabetic Torii (SDT) rat is an inbred strain of Sprague-Dawley rat and recently is established as a nonobese model of type 2 diabetes (T2D). Male SDT rats show high plasma glucose levels (over 700 mg/dL) by 20 weeks. Male SDT rats show pancreatic islet histopathology, including hemorrhage in pancreatic islets and inflammatory cell infiltration with fibroblasts. Prior to the onset of diabetes, glucose intolerance with hypoinsulinemia is also observed. As a result of chronic severe hyperglycemia, the SDT rats develop profound complications. In eyes, retinopathy, cataract, and neovascular glaucoma are observed. Proliferative retinopathy, especially, resulting from retinal neovascular vessels is a unique characteristic of this model. In kidney, mesangial proliferation and nodular lesion are observed. Both peripheral neuropathy such as decreased nerve conduction velocity and thermal hypoalgesia and autonomic neuropathy such as diabetic diarrhea and voiding dysfunction have been reported. Osteoporosis is another complication characterized in SDT rat. Decreased bone density and low-turnover bone lesions are observed. Taking advantage of these features, SDT rat has been used for evaluating antidiabetic drugs and drugs/gene therapy for diabetic complications. In conclusion, the SDT rat is potentially a useful T2D model for studies on pathogenesis and treatment of diabetic complications in humans.