Two populations of bone marrow cells creating an ectopic hematopoietic focus

A fragment of bone marrow transplanted beneath the capsule of the kidney creates a focus of ectopic hematopoiesis the size of which, measured according to the number of hematopoietic cells, is proportional to the size of the implant. In irradiated recipients the focus was 1.5–2.5 times larger than in intact recipients. Cells creating a focus of heterotopic hematopoiesis in intact and irradiated recipients differed in their radiosensitivity: their D₀ values were about 160 and 350 rad, respectively. In this connection it is postulated that two populations of precursor cells participate in the creation of the focus. Their possible relations with predetermined and inducible osteogenic precursor cells are discussed.Laboratory of Bone Marrow Culture and Transplantation, Central Institute of Hematology and Blood Transfusion, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Fedorov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 2, pp. 206–208, February, 1977.