EN
It is analyzed morphofunctional features of Hirudo verbana tissues on histological sections in order to determine the possible causes of their partial death after hirudotherapeutic procedure. In the study was taken 4 groups of leeches: hungry (control), healthy well-fed, well-fed that vomited blood and well-fed dead. Morphofunctional changes in midgut of healthy well-fed H. verbana compared to the hungry are the changes of epithelium height through stretching eaten blood. In well-fed that vomited blood and well-fed dead leeches in the intestinal epithelium were observed degenerative processes that are accompanied by a decrease in the height of the epithelium, its partial desquamation. Botryoidal tissue of hungry leeches is in an inactive state, in healthy well-fed ones it responds with an increased physiological vascularization, activation of some botryoidal granulocytes with an increase in their average size, on receipt of the products of digestion. Activation of some botryoidal granulocytes, without a significant increase in their sizes, in well-fed leeches that vomited eaten blood and well-fed dead leeches, with increased infiltration of the adjacent connective tissue lymphocyte- and macrophage-like cells, amebocytes and granulocytes indicates the development of pathological processes, which are resulting in immunological conflict between eaten human blood and leeches’ tissue microenvironment.