Aim. To study the activity of myeloperoxidase in the peripheral blood of pregnant women in normal and thyroid diseases. Materials and methods. Cytochemical analysis was used to study the activity of myeloperoxidase in peripheral blood neutrophils of pregnant women with diffuse toxic goiter, as well as in women with the physiological course of pregnancy in a comparative aspect. Results. It was found that in women with a physiological course of pregnancy, the cytochemical parameters of myeloperoxidase in neutrophils were reduced only in the 1st trimester of pregnancy. In patients with diffuse toxic goiter, with severe thyrotoxicosis syndrome, the activity of the enzyme was significantly reduced during all periods of pregnancy. Apparently, these shifts of the enzyme, which is the main component of the protective system of blood phagocytes, are associated with their functional stress. Conclusion. Based on this opinion, it seems that blood neutrophils enter the system of thyroid hormone metabolism by their degradation. Apparently, this mechanism is activated with an increased content of hormones in the circulation, which occurs during pregnancy, and especially with concomitant diffuse toxic goiter with thyrotoxicosis syndrome and is aimed at preserving homeostasis necessary for normal fetal development.
