Changes in the microscopic organisation of rat adrenal glands under the influence of Vipera berus berus venom

Snakebite envenoming is a common but neglected public health problem worldwide. Annual mortality as a result of snakebites exceeds 138,000. The organs of the endocrine system are among the first to react to the effects of snake and viper toxins. Under these conditions, the adrenal glands are involved in the pathological process and contribute to the formation of the adaptation syndrome, undergoing complex structural changes. The research aims to study the changes in the microscopic organization of the adrenal glands of rats under the influence of Vipera berus berus venom. Experimental studies were carried out on white non-linear male rats. The animals were conditionally divided into a control and an experimental group of 10 individuals. Experimental rats were injected intraperitoneally in a saline solution with a semi-lethal dose (LD50) (1.576 mg/g-1) of Vipera berus berus venom. Animals of the control group were injected intraperitoneally with only saline solution. Rats were removed from the experiment 24 hours after exposure to the venom and anaesthetized by decapitation. Adrenal gland samples were taken for microscopic examination. Fixation of the material and preparation of paraffin blocks were carried out according to generally accepted methods. Histological preparations of the adrenal glands were stained with hematoxylin and eosin. Histological preparations were studied using an SEO SСAN light microscope. Under the influence of Vipera berus berus venom in zona glomerulosa of the adrenal cortex, moderately pronounced pathological changes were found, including vacuolization and granularity of the cytoplasm of endocrinocytes, loss of precise contours of nuclei, their hyperchromasia, expansion of lumens of sinusoidal capillaries, accumulation of erythrocytes in them. Under these conditions, zona fasciculata is characterized by significant cell granularity and perinuclear edema. Less pronounced structural organization changes were noted in the zona reticularis of the adrenal cortex. Endocrinocytes of this zone had small sizes, eosinophilic cytoplasm and dark nuclei. In the medulla of the adrenal glands, the cells were large in size and had indistinct contours, the cytoplasm was characterized by basophilic granularity, and the nuclei were light due to the predominance of euchromatin. The most pronounced effect of Vipera berus berus venom was on the zona glomerulosa and zona fasciculata of the adrenal cortex; most of the morphological signs of pathology in which were caused by a violation of protein metabolism in the cells of the parenchymal and stromal elements of this organ.