Abstract
Purpose::
To compare the development of diabetic retinopathy in two animal models of type 2 diabetes.
Methods::
A group of five neonatal Wistar rats was treated with an intraperitoneal injection of streptozotocin, 90 mg/kg, at day 2 of age. Another group of five neonatal Wistar rats received an ip injection of streptozotocin, 45 mg/kg, at day 2 of age, and begun to be feeded with a high-fat-diet from week eight onwards. A control group was made up of five Wistar non-diabetic rats. Animals were sacrificed and the eyes extracted at 36 weeks. The retinas were processed for immunohistochemical and histological analysis. In some cases the tripsine digestive technique was used to identify microvascular changes, and to count pericytes and endothelial cells.
Results::
Diabetic groups had a higher expression of GFAP than controls. A significantly lower number of pericytes, presence of vessels dilatations and other microvascular abnormalities were only found in rats feeded by a high-fat-rich diet.
Conclusions::
The progression of diabetic retinopathy was faster in animals with initial less pancreatic injury and a high-fat-rich diet. Results may be useful to better understand diabetic retinopathy development and to elaborate therapeutical strategies.
Keywords: diabetic retinopathy • retinal glia • Muller cells