The aim of the work: to study morphological changes in the kidneys of experimental rats under the conditions of administration of Vipera berus nikolskii viper venom. Materials and Methods. The animals were divided into two groups: control and experimental, each with 10 individuals. Experimental rats received an intraperitoneal injection of a semi-lethal dose (LD50) of Vipera berus nikolskii venom in saline, at a concentration of 0.972 mg·g-1. The control group was administered only saline. After 24 hours, the rats were euthanised by decapitation after anaesthesia. Histological preparations were examined under a SEO SСAN light microscope and recorded using a Vision CCD camera equipped with an image output system. Results. Histological analysis of the effect of the venom of the viper Vipera berus nikolskii on the kidneys demonstrated the presence of big destructive changes in the animal organ. This is due to the powerful combination of venom phospholipases A2 and metalloproteinases, which leads to systemic cytolysis and vasopathy. Total disorganisation of the order of the renal corpuscles, phenomena of glomerular necrobiosis, and desquamation of the outer leaf of the Shumlyansky-Bowman capsule are observed. Pronounced lymphohistioplasmocytic infiltration of the organ parenchyma is noted. Morphological changes in the epithelium of the renal nephron tubules under these conditions have the character of acute necrotic nephrosis. Conclusions. Intoxication with the venom of the viper Vipera berus nikolskii causes the development of acute necrotic nephrosis. There is a transition from dystrophy to coagulative necrosis, with massive karyorrhexis, karyolysis, and the formation of structureless cellular detritus. Multiple extravasations and extensive hemorrhagic foci in the cortical substance are noted. Received: 09.01.2026 | Revised: 03.02.2026 | Accepted: 19.02.2026
К.М. Агафонов (Mon,) studied this question.