Ecotoxicological aspects of continental water bodies biotic factors analysis

The article highlights the place of hydroecology in the system of biological sciences and the contribution of its achievements to the development of such an integrative field of activity of scientists and educators as medical biology, analyzes the ecotoxicological aspects of the presence in continental water bodies of those factors that can directly or indirectly affect the life of aquatic animals and humans, as well as for the implementation of public needs in water resources. Attention is focused on the biotic factors associated with the «water bloom» phenomenon, in particular on those cyanobacteria that are producers of compounds toxic to humans and certain animals. Approaches to elucidating the ways in which aquatic animals and humans are affected by the toxic components of cyanobacteria are considered. In this regard, the deficiency of vitamin В1 caused by them in the affected animal body is mentioned, as well as the need for thiamine, in particular, to ensure effective maintenance of neuromuscular transmission. It is emphasized that contact with cyanobacteria and certain products of their vital activity during the «water bloom» period can have extremely negative consequences for humans, therefore such compounds – cyanotoxins – are classified based on the nature of the main symptoms of intoxication caused by them in the affected body. At the same time, the following groups of cyanotoxins are distinguished: hepatotoxins; neurotoxins; dermatoxins. Attention is focused on hepatotoxins microcystin, nodularin, and cylindrospermopsin, neurotoxins anatoxin-a, guanitoxin, and saxitoxin, which are particularly dangerous for humans and animals, as well as structural analogs of natural origin of the named compounds. Producers of relevant cyanotoxins, ways of accumulation of these compounds in aquatic animals, ways of cyanotoxins entering the human body and warm-blooded animals are given. The mechanisms of action of specific hepatotoxins and neurotoxins, which selectively interact with the corresponding cellular structures sensitive to them, causing disruption of vital processes, are analyzed in the named organisms. The need for acquiring knowledge about cyanotoxins and their producers by students of higher education, who are trained in medical specialties, is discussed.