The paper shows features of the immune system of poikilothermic aquatic organisms of different taxonomic groups: crustaceans, fish, and amphibians. Defense mechanisms of crustaceans are presented by largely innate non-specific factors: external covers (including the exoskeleton), mucus, physical and chemical barriers lysozyme in the hemolymph, propanolamine system, and phagocytosis. The authors identified 4 types of cells (hemocytes) found in the circulating fluid of crayfish, depending on the morphological and functional properties: agranulocytes, progranulin,granulocytes, and transparent cells. Each type performs different functions in the process of immune defense. In fish, there is no red bone marrow and lymph nodes, the main organs of hematopoiesis include thymus, spleen, liver, lymphoid tissue of the brain and the trunk of the kidneys,accumulation of lymphoid tissue of the cranial box, intestine, and pericardium. Humoral components of the immune response of fish are represented by immunoglobulins, system complement components, lysozyme, C-reactive protein, interferon, lysine, hemolysin, hemagglutinin. Only IgM-like antibodies represent immunoglobulins in fish. The central organ of the amphibian immune system is the red bone marrow, but its role in the immune defense of amphibians has not been sufficiently studied. Peripheral organs of the immune system include kidneys, thymus, spleen, lymphomyeloid organs. Depending on the characteristics of the immune system of poikilothermic hydrobionts of different types, the authors offer methods for assessing their humoralimmunity (by determining phenoloxidase) and cellular response (by phagocytosis). Cellular immunity, and phagocytic activity, in particular, can be evaluated using cytochemical methods taking into account oxygenindependent factors – the content of enzymatic lysosomal cationic protein in phagocytes – and oxygendependent ones – NBT-test with nitrosonium tetrazolium that records cytotoxic oxygen radicals generated during the respiratory explosion of cell stimulation in vitro.
The ICRP recommended methods of red bone marrow dosimetry