UDC: 61:612.4:615.9.616.4:616-09

Snakebite envenoming is a common but neglected public health problem worldwide, especially in tropical countries. Annual mortality as a result of snakebites exceeds 138,000. It is believed that this problem is underestimated, and in many countries, individual cases of bites are not subject to proper fixation. The purpose of the study is the analytical and quantitative assessment of the structural components of the rats' adrenal glands under exposure to the venom of Vipers Vipera berus berus and Vipera berus nikolskii. Experimental studies were carried out on white, non-linear male rats. Vipera berus berus and Vipera berus nikolskii viper venom were obtained from V. N. Karazin Kharkiv National University. The freeze-dried native venom was stored at
-20 °C and dissolved in saline immediately before the experiment. The animals were divided into three groups (control and 2 experimental groups) of 10 individuals each. Experimental rats were injected intraperitoneally in a physiological solution with a semi-lethal dose (LD50) (1.576 mg/g-1) of Vipera berus berus and Vipera berus nikolskii venoms. Animals of the control group were injected intraperitoneally with only a physiological solution. Rats were removed from the experiment 24 hours after exposure to the poison and anesthetised by cervical dislocation. Statistical analysis of the area
of the microcirculatory channel and the nuclear-cytoplasmic index was performed using Fiji: ImageJ program and processed in Excel. Administration of the venom of the vipers Vipera berus berus and Vipera berus nikolskii to rats was accompanied by a significant increase in the area of the microcirculatory bed relative to the control group (2.9 times for Vipera berus berus and 6.5 times for Vipera berus nikolskii). Exposure to Vipera berus berus viper venom was associated with a significant decrease in the nuclearcytoplasmic index in rats of the experimental group compared to the control group (13 % and 42 %, respectively), which is evidence of a decrease in the area of the nuclei of endocrinocytes of the adrenal cortex. This indicator in rats under the administration of Vipera berus nikolskii venom was even lower and amounted to 12 %. According to the statistical analysis of the quantitative assessment of the state of the cortical substance of the adrenal glands, it is worth noting the similar effect of the poisons of both types of snakes at the cellular level. At the same time, at the tissue level, the effect of Vipera berus nikolskii venom is more pronounced than that of Vipera berus berus - this is evidenced by the higher degree of disruption of the structure of the hemomicrocirculatory channel in the adrenal cortex of animals from the group that was affected by this venom. It led to an increase in the area of vessels due to their expansion and ruptures of their walls and haemorrhages into the surrounding parenchyma and stroma.