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Journal of Diabetes Research
Volume 2014, Article ID 672590, 7 pages
Research Article

Effect of Ranirestat, a New Aldose Reductase Inhibitor, on Diabetic Retinopathy in SDT Rats

1Department of Ophthalmology, Saitama Medical Center, Jichi Medical University, 1-847 Amanuma-cho, Omiya-ku, Saitama 330-8503, Japan
2Drug Development Research Laboratories, Sumitomo Dainippon Pharma Co., Ltd., 6-8-2 Doshomachi, Chuo-ku, Osaka 541-0045, Japan

Received 11 July 2014; Revised 1 August 2014; Accepted 4 August 2014; Published 25 August 2014

Academic Editor: Tomohiko Sasase

Copyright © 2014 Fumihiko Toyoda 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.


Purpose. To evaluate the effect of ranirestat, a new aldose reductase inhibitor (ARI), on diabetic retinopathy (DR) in Spontaneously Diabetic Torii (SDT) rats. Methods. The animals were divided into six groups, normal Sprague-Dawley rats , untreated SDT rats , ranirestat-treated SDT rats (0.1, 1.0, and 10 mg/kg/day, , and , resp.), and epalrestat-treated SDT rats (100 mg/kg/day, . Treated rats received oral ranirestat or epalrestat once daily for 40 weeks after the onset of diabetes. After the eyes were enucleated, the retinal thickness and the area of stained glial fibrillary acidic protein (GFAP) were measured. Results. The retinas in the untreated group were significantly thicker than those in the normal and ranirestat-treated (0.1, 1.0, and 10 mg/kg/day) groups. The immunostained area of GFAP in the untreated group was significantly larger than that in the normal and ranirestat-treated (1.0 and 10 mg/kg/day) groups. There were no significant differences between the untreated group and epalrestat-treated group in the retinal thickness and the area of stained GFAP. Conclusion. Ranirestat reduced the retinal thickness and the area of stained GFAP in SDT rats and might suppress DR and have a neuroprotective effect on diabetic retinas.