An electron‐ and light‐microscope study of sinus structure in perfused rabbit and dog spleens

Abstract

Abstract The removal of blood cells by low‐pressure perfusion produced well‐delineated views of the sinus wall in rabbit and dog spleens. The sinus wall contained three elements: an inner layer of sinus cells, an intermediate layer of basement membrane, and an outer layer of cord‐limiting cells. Sinus and cord‐limiting cells, apparently similar to each other in cytoplasmic detail, appeared to be reticular cells that possessed only a limited capacity for phagocytosis of gold particles. Apertures in the sinus wall enabled blood cells to pass through the wall. Many apertures in perfused spleen contained no cells and yet remained patent. Sinus cells often were contiguous and commonly did not alternate with apertures. However, sinus‐cell interdigitation was slight, and evidence for tight junctions and desmosomes between sinus cells was inconclusive.