Indirect effect of substances of the hemophagous parasite Hirudo verbana on the immune system of the host rats.

A positive relationship between the hematophagous parasite-medicinal leech and the host (animals and humans) has been partially shown by many authors. But only direct influence was shown, and how they can influence indirectly has not been studied by anyone. Therefore, it became relevant to analyse the immunological parameters of blood and histological analysis of the central lymphoid organ of female rats on the 30th day after the birth of their offspring, as well as the same indicators in their offspring on the 30th and 60th days of ontogenesis under the indirect influence of saliva substances of the hematophagous parasite Hirudo verbana. The parasite attachments were carried out to male rats before mating; after four attachments, males were added to the females. After pregnancy, the females were removed. The analysis of indicators was carried out according to the goal. We counted the number of erythrocytes and leukocytes, analysed the leukocyte blood count, studied the phagocytic and metabolic activity of neutrophils, histologically analysed the thymus, carried out a statistical analysis. Under the indirect influence of the substances of the parasite saliva, in experimental female rats and their offspring, in comparison with the control group, a significant increase in the number of leukocytes and erythrocytes is observed. The leukocyte blood count in the experimental group remains unchanged in females and their offspring in comparison with the control. When analysing the thymus in the experimental group, the number of lymphocytes significantly increases in females and their offspring. Substances of the hematophagous parasite are able to indirectly positively influence the general condition of pregnant female rats, and later their offspring. It should be noted that the parasite did not directly affect females and their offspring.