RESEARCH ARTICLE
Effects of Topical Nipradilol on Early Diabetic Retinopathy in SDT Rats
Nozomi Kinoshita, Akihiro Kakehashi*, 1, Yoh Dobashi1, Ryuichiro Ono1, Fumihiko Toyoda1, Chiho Kambara1, Hiroko Yamagam1, Yusuke Kitazume2, Eiji Kobayashi3, Yasuhiro Osakabe4, Motoshige Kudo4, Masanobu Kawakami1, Yasunori Kanazawa5
Article Information
Identifiers and Pagination:
Year: 2011Volume: 4
First Page: 114
Last Page: 118
Publisher Id: TODIAJ-4-114
DOI: 10.2174/1876524601104010114
Article History:
Received Date: 21/07/2010Revision Received Date: 25/10/2010
Acceptance Date: 15/01/2011
Electronic publication date: 28/3/2011
Collection year: 2011
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abstract
We tested the effect of topical nipradilol, an antiglaucoma drug with α- and β-blocker and nitric oxide (NO) donor activities, on the early retinal changes using electron microscopy in Spontaneously Diabetic Torii (SDT) rats. In seven young male SDT rats (17 to 18 weeks old), nipradilol solution was instilled in the right eyes and nipradilol-free base solution in the left eyes three times daily for 3 months. All rats were sacrificed and both eyes were enucleated for electron microscopy at the end of the experiments. All rats had blood glucose levels exceeding 350 mg/dl within 2 weeks after the beginning of the experiment (mean final blood glucose level, 558±100.2 mg/dl). In untreated eyes of young SDT rats, the overall pathological features were almost comparable to those in older SDT rats, although the pinocytotic vesicles and free ribosomes were not as remarkable in the latter. In contrast, in nipradilol-treated eyes of SDT rats, although the basement membrane was thickened, microvilli were seen, and a larger number of electron-dense mitochondria were in the wide cytoplasm. Lipofuscin-like electron-dense granules and lamellated myelin figures also were identified. Nipradilol reduced the early morphologic changes in the endothelial cells, which reflects the metabolically active state of diabetic retinopathy in SDT rats through its action as a NO donor.