Osteogenesis in transplants of bone marrow cells

Abstract
After heterotopic (e.g. subcutaneous) transplantation of bone marrow, haemopoiesis in the graft ceases; reticular tissue develops instead, and later bone is formed (Denis, 1958). The result can be achieved by grafting either free pieces of bone marrow or those placed in diffusion chambers (Petrakova, Tolmacheva & Friedenstein, 1963; Rosin, Freiberg & Sajnek, 1963). In the case of free transplantation the bone formed is later filled with bone marrow. After transplantation in diffusion chambers haemopoiesis does not recur despite the development of a considerable mass of bone in the chambers (Friedenstein, 1965). The population of bone marrow cells is very heterogeneous, including haemopoietic cells, reticular cells and endosteum elements. According to generally accepted views this population is a mixture of individual cell lines capable of mutual transformations within certain limits (Maximov, 1927; Burwell, 1964). After transplantation some of the pathways of differentiation open to bone marrow tissue (formation of reticular and bone tissues) are stimulated, while others (haemopoiesis) are arrested.