Enhancement of angiogenesis by the implantation of self bone marrow cells in a rat ischemic heart model

Background. Bone marrow contains various kinds of primitive cells which dif ferentiate into endothelial cells and could secrete several growth factors. Therefore, we attempted to induce therapeutic angiogenesis using self bone marrow cells in a rat model. Materials and methods. Quantitative angiogenesis was examined using a spong e implantation assay that indicated whether the rat bone marrow cells had i nduced angiogenesis or not. Employing a rat ischemic heart model, bone marr ow cells were injected directly into the ischemic area and the number of ve ssels was examined immunohistochemically using the anti-CD31 monoclonal ant ibody. The contributed growth factors revealed the levels present in the is chemic myocardium by an enzyme-linked immunosorbent assay and reverse trans cription polymerase chain reaction. Results. The sponge implantation assay showed that bone marrow cells induce d angiogenesis. Light microscopic analysis of the vessel count positively s tained by anti-CD31 in the ischemic area showed that angiogenesis had been induced to a significantly greater degree in the group implanted with bone marrow cells (BMI group) than in the group injected with phosphate-buffered saline (PBS group) 1 week after BMI. Levels of the inflammatory cytokines interleukin-1 (IL-1 beta) and cytokine-induced neutrophil chemoattractant ( CINC) in the BMI group were significantly elevated compared with those in t he PBS group. Conclusions. Self bone marrow cell implantation induced angiogenesis in a r at ischemic heart model as a result of elevation of the levels of IL-1 beta and CINC. Thus, bone marrow implantation could be a novel and simple metho d to induce therapeutic angiogenesis. (C) 2000 Academic Press.