Comparison of the Pathological Picture of Experimental Diabetic Nephropathy in Rats at Early (1 month) and Late (8 months) Stages

Abstract

The research objective was to investigate the pathological picture of diabetic nephropathy (DN) in the 8-month streptozotocin (STZ)-induced diabetes mellitus (DM) and compare it with the previously obtained picture of DN in the 1-month STZ-induced DM. Materials and methods: Experiments were conducted on 15 male Wistar rats aged 2-3 months and weighing 250–280g. To induce DM, the animals were injected intraperitoneally 1ml of STZ solution in the citrate buffer at a dose of 65mg/kg. In accordance with modern ideas about the peculiarities of DM modeling using STZ for more selective modeling of type 2 DM, the rats were previously injected with an intraperitoneal solution of cytoflavin based on a nicotinamide dose of 115mg/kg. After 8 months of the experiment, the concentration of glucose, protein, and creatinine was determined in urine. The animals were euthanized under ethereal anesthesia and both kidneys were extracted, cleaned and washed with a physiological solution. In the renal tissues of animals, we determined the concentration of thiobarbituric acid reactive products, total pro-oxidant activity, total antioxidant activity, activity of antioxidant enzymes (catalase, superoxide dismutase, and glutathione peroxidase). With the help of a morphometric method of research, the area of renal glomeruli and the area of capillary lumens were measured, and after a special computer processing of digital photos, the total area of the vascular bed in the glomerulus and the area of mesangium in the renal glomerulus were assessed. Results: DN in the 8-month STZ-induced DM was more pronounced than with the 1-month STZ-induced DM. The revealed biochemical and morphological signs of the 8-month STZ-induced DM indicate the irreversible nature of its course and the impossibility of its pharmacological correction.

Keywords

• diabetes mellitus
• streptozotocin
• diabetic nephropathy