The study on the morphology character of blood-spleen barrier

Objective To study the morphology and functional character of blood-spleen barrier(BSB) and establish the concept of BSB. Methods Thirty healthy Wistar rats were studied. Ten rats were injected with 1.5 ml mixed fluid of India ink and physiological saline through the tail vein. Histological changes of the spleen in all animals were observed with light and electron microscopy, including HE, Foot, Masson staining and immunohistochemistry of CD68 and CD34. Results Most of the carbon particles were within the splenic sinuses in marginal zone but not in the white pulp after 6 h. There was a characteristic distribution of the macrophagocytes, vessel endothelial cell, reticular tissue and collagen fiber in the BSB. Conclusions BSB, surrounding the white pulp, is composed of macrophagocytes, marginal-sinus-endothelial cells and their basement membrane, the reticular tissue (reticular cells and reticular fibers) and collagen fibers. The role of BSB is to keep the microenvironment of white pulp stable. It becomes mature while the formation of germinal center of the white pulp. The permeability of BSB changes during its development.