Heterotopic sternum transplant in rats: A new model of a vascularized bone marrow transplantation.

We introduced the heterotopic vascularized sternum transplant as a more simple and pure alternative to allogeneic hind limb transplantation for the study of bone marrow transplantation. We report the clinical and histopathological manifestations after transplantation of syngeneic and allogeneic sternal grafts with and without immunosuppression with FK-506. Syngeneic grafts maintained normal histology, whereas allografts showed rejection, which was prevented by FK-506. FK-506-treated allografts developed chimerism that was present throughout the observation period. Transplantation of the sternum may be a valuable model to study vascularized bone marrow transplantation and its effects on repopulation of bone marrow of the host, chimerism, and tolerance.