Abstract
Purpose::
examine retinal changes in the long term of type 2 diabetic rats with a high-fat diet.
Methods::
Wistar rats were injected with streptozotocin (STZ) at the age of two days with 45 mg/kg ip. At the age of 8 weeks the animals were fed with a high-fat diet. Four diabetic and four normal control animals were euthanized at the age of 36 and 80 weeks, respectively. Cross sections of retinas were analyzed by immunohistochemistry and immunofluorescence using GFAP and RAGE antibody. Histological changes by Hematoxiline & Eosin and PAS.
Results::
Cross sections of the retina revealed that GFAP-positive cells had the morphology and spatial organization of Muller cells in the three groups of diabetic rats. Rage immunoreactivity was much higher in diabetics of 80 weeks. Histology revealed the presence of neovessels and proliferative vitreoretinopathy changes in the group of old diabetic rats.
Conclusions::
The moderate retinal changes found in rats of 36 weeks of age were followed by proliferative diabetic retinopathy development at 80 weeks of age. This in vivo model may be useful to evaluate the mechanism of early retinal damage in type 2 diabetes and to study the effect of diet in the progression of diabetic retinopathy.
Keywords: diabetes • retina • astrocyte