IMMUNOMORPHOMETRIC INDICES OF RATS AFTER ADMINISTRATION OF POLYOXOMETALATES

Abstract

The impact of nanoparticles containing metal oxides can cause both increased proliferation and death of immunocompetent cells. Polyoxometalates (POM) are nanoparticles containing iron (III) and molybdenum oxides. POMS are intended for targeted transport of drugs. Nanoparticles may produce effects that differ from those of the mixture of compounds contained in the nanoparticles. The aim of the work is to investigate the effect of POM and a mixture of POM components (derivatives) on the morphometric parameters of the thymus, spleen, the number of blood leukocytes and their precursors in the bone marrow. Materials and methods.The study was conducted on 25 mature male Wistar rats divided into 5 equal groups: animals in groups 1 and 2 were injected intramuscularly with POM once and seven times, animals in groups 3 and 4 were injected with derivatives also once and seven times, the first group was left intact. A single dose of POM or derivatives was 0.15 mg / 100 g of body weight. The cortical-medullar index of the thymus and morphometric parameters of the spleen (area of ​​the stroma, white pulp, lymphoid follicles, and width of the mantle and marginal zones of lymphoid follicles) were calculated. Based on the morphometric parameters, the coefficients used for the integral assessment of morphometric changes in the spleen were calculated: stromal-parenchymatous ratio (SPR), follicular coefficient (FC), and lymphoid coefficient (LC). The number of leukocytes and their fractions in the peripheral blood, the number of leukocyte precursors in the bone marrow were determined. Research results.When comparing the parameters of rats given POM and derivatives with the parameters of intact rats, the following was established: no reliable differences in the ratio of the cortex and medulla of the thymus; an increase in the SPR in group 3, SPR, FC and the width of the marginal zone in group 5. In groups 2-5, leukopenia was detected due to a deficiency of granulocytes. When derivatives were administered, the number of lymphocytes also decreased in groups 4-5. An increase in the number of monocytic cells was detected in the bone marrow in groups 3 and 5. Conclusions. Changes in the peripheral organ of immunopoiesis, namely hyperplasia of the lymphatic apparatus of the spleen, are observed to a greater extent under the action of individual components of nanoparticles (derivatives) than under the action of polyoxometalates. The action of POM and derivatives is less pronounced in the central organs of the immune system: the thymus and bone marrow. Compensation of the leukocyte deficiency in the blood occurs mainly due to leukopoiesis in the spleen.