STUDY OF CHANGES IN CARBOHYDRATE METABOLISM AND THE MORPHOLOGICAL STATE OF THE RAT RETINA UNDER CONDITIONS OF EXPERIMENTAL DIABETIC RETINOPATHY
DOI:
https://doi.org/10.11603/mcch.2410-681X.2026.i3.16763Keywords:
diabetes mellitus; diabetic retinopathy; histological characteristics; carbohydrate metabolism; streptozotocin, retinaAbstract
Background. Diabetic retinopathy is a primary microvascular complication of diabetes mellitus and a leading cause of vision loss. Persistent hyperglycemia induces profound disturbances in carbohydrate metabolism, initiating metabolic, vascular, and neurodegenerative changes in the retina. Experimental models are essential to understand the temporal relationship between metabolic dysregulation and structural retinal damage. Aim. To study changes in carbohydrate metabolism parameters and the morphological state of the rat retina under conditions of streptozotocin-induced diabetic retinopathy. Materials and Methods. The study was performed on 30 white outbred rats weighing 180–200 g. Diabetic retinopathy was induced by a single intravenous injection of streptozotocin (65 mg/kg) against the background of nicotinamide (230 mg/kg). Body weight dynamics, blood glucose levels, and glycated hemoglobin (HbA1c) were evaluated on days 60 and 120. Retinal morphology was assessed by histological analysis (hematoxylin and eosin staining). Results. Rats with streptozotocin-induced diabetes showed significantly elevated blood glucose and HbA1c levels on days 60 and 120 compared with intact controls. HbA1c concentration reached 7.6 ± 0.5 % on day 60 and 10.4 ± 0.8 % on day 120 (vs 5.8 ± 0.6 % in intact animals, p < 0.05). Histological examination at day 60 revealed alterations in the inner and outer nuclear layers without pathological neovascularization, consistent with a nonproliferative stage. By day 120, a pronounced reduction in bipolar cell density and the appearance of neovascular foci indicated transition to the proliferative stage of diabetic retinopathy. Conclusions. Streptozotocin-induced diabetes leads to progressive metabolic disturbances and timedependent morphological remodeling of the retina. These findings confirm the close association between chronic hyperglycemia and structural retinal damage, supporting the relevance of this model for studying the stages of diabetic retinopathy.
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