Purpose: This article is devoted to the investigation of the structural features of the bone marrow of mature rats.
Materials and methods: The investigation of the structural features of the bone marrow was performed on the femurs of the mature male rats. General structure of the organ was studied with hematoxylin-eosin and Van Gieson staining of samples. Certain features of the bone marrow structure were studied using immunohistochemical method (CD3, CD79α, S100, myeloperoxidase, and cyclin D1).
Results: We can state that stromal-parenchymal structure is typical for the bone marrow of rats as for any other organ. The stromal component is presented with bone tissue (48.8 ± 3.3% at epiphyses), the net of blood vessels (18.7 ± 2.1%), fat tissue (11 ± 2%), fibrous tissue (0.7 ± 0.2%), and the network of reticular fibers. Hematopoietic tissue covers 20.9 ± 3.7% at the femoral epiphyses and 69.6 ± 2.2% at diaphysis. Among these tissues, myelopoiesis occupies 74.2 ± 4.7%, erythropoiesis - 24.3 ± 4.7%, and lymphopoiesis - less than 5%. Megalokaryocytes take 0.1-0.3%.
Conclusion: Considering the lack of significant anatomical, morphological, and histological differences of red bone marrow of rats and humans, we can state that hematopoiesis in rats takes place on the basis of the same principles as in humans, although it has certain mechanisms.
Keywords: bone marrow; erythropoiesis; immunohistochemical method; lymphopoiesis; megalokaryocytes; myelopoiesis.