Age-specific features of formation of hemopoietic microenvironment by stromal precursors from bone marrow of thymectomized mice

Heterotopic transplantation of bone marrow demonstrated that the content of stromal precursor cells capable of hemopoietic microenvironment transfer does not depend on thymus function. Thymectomy of bone marrow donors involves a decrease in the size of foci formed in young donors and an increase in old recipients. The results indicate a thymus-dependent regulation of proliferation of stromal precursors and/or their factor-sensitive category, determining the proliferation of recirculating stem hemopoietic cells. The size of ectopic hemopoiesis focus depends on the age of recipient. Transplantation of syngeneic thymus under renal capsule of thymectomized mice abolished the effect of thymectomy. Osteogenic activity of stromal precursors correlates with the age of bone marrow donors. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 4, pp. 457–459, April, 1998