Objective: Introduction: The spleen is a multifunctional odd organ, which is a biological filter, but its structure in experimental animals is not fully understood.
Patients and methods: Materials and methods: The ultramicroscopic structure of the cells and vessels of the spleen of amphibian animals (Pelophylax lessonae С. - the pool frog and Pelophylax ridibundus Р. - the marsh frog) are elucidated in the research.
Results: Results: The cytopupulation of the spleen is formed by lymphocytes, neutrophils, erythrocytes, macrophages, plasma cells etcetera. A feature of the cellular composition of the parenchyma of the spleen of the frogs is a significant number of neutrophilic eosinophils. The organelles, which situated in the cell cytoplasm, are characteristic of somatic cells. The endothelial lining and the structure of the capillary basement membrane, which has the form of a plate, formed from 8-12 endothelial cells, grouped in complexes and adjoining contacts in adjacent zones, are experimentally substantiated by the somatic type of vascular endothelium of the microcirculatory channel. Such cells are contained on the basal membrane, surrounded by a dense interlacing of collagen, elastic fibers and the main substance, and the sites of endothelial cell adhesion have the uneven contours. The nuclei of the endothelial cells are surrounded by a cytoplasm on all sides, which reveals foamy cysts.
Conclusion: Conclusions: The results obtained are of great interest for evolutionary immunomorphology, the extrapolation of which improves understanding of microcirculation, transport of substances in the spleen, and mechanisms for formation of the immune response.
Keywords: blood vessels; electron microscopic research; spleen; endothelial cells; frog.