Purchase this article with an account.
R. Salceda, V.M. Coffe, J. Hernández-Berrones; Glycogen Levels in the Normal and Diabetic Rat Retina . Invest. Ophthalmol. Vis. Sci. 2003;44(13):3879.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose:To better understand glucose metabolism in retina, we studied the glycogen content and its role as energetic storage in normal and diabetic rat retina. Methods: Long Evans rats were used. Retinas were incubated at 37°C in Krebs medium under dark and light conditions, and in the presence of different glucose concentrations. Glycogen levels were determined by the procedure of Lust et al., 1975 and Keppler and Decker, 1983. Protein content was determined using a commercial kit assay (Bio Rad DC). Diabetes was induced by a single intraperitoneal administration of streptozotocin (97 mg/kg) in 0.05 M citrate buffer, pH 4.5. Animals were used 7-60 days after treatment. Treated animals with glycemic levels below 16 mM were not included. All studies were carried out according with ARVO statements for the use of animals. Results: Ex vivo retinas from light or dark-adapted normal animals showed glycogen values of 44 ± 0.3 and 19.5 ± 0.4 nml/mg put, respectively. In the retina from light-adapted animals and incubated under dark conditions, the glycogen levels decreased about 50%, while the same values were found when retinas were incubated under normal room illumination. In the absence of glucose, glycogen content decrease (40-65%) in both dark and light incubation conditions. High glucose concentration (20 mM) caused a considerable increase (50-70%) in glycogen content.Ex vivo retinas from setreptozotocin treated rats, showed glycogen levels 100% higher than the normal ones. Conclusions: In the retina, glycogen levels are regulated by glucose concentrations and physiological conditions. Glycogen storage appears to be altered in diabetes.
This PDF is available to Subscribers Only