In the present study, we compared the extravasation of albumin in retinal and renal tissues, between diabetic and non-diabetic (control) animals. Male Whistar rats were made diabetic by single intraperitoneal injection of Alloxan, and another control group received vehicle. 6 weeks after Alloxan treatment, permeability of blood-retinal barrier and renal vessels were measured by the extravasation of fluorescein isothiocyanate labeled bovine serum albumin (FITC-BSA) using a fluorescence microscope. Fluorescence was assayed with an image processing program, comparing the retina and renal tissues. Tissue fluorescence was compared with serum fluorescence, measured with a spectofotometer. Results: We compared for the first time retinal and renal vascular permeability changes in diabetic animals. The difference between the control and diabetic group was statistically significant. A positive correlation could be observed between the retina and kidney tissue fluorescence. The fluorescence of different retinal layers could be measured separately, while the average was in concordance with serum fluorescence. The presented method can be used for testing different drugs, in their impact to the permeability changes of retinal and renal vessels in diabetes.
Keywords: diabetic retinopathy, experimental diabetes, Alloxan, FITC-BSA, vascular permeability