Origination of stromal precursor cells replenishing the population of these cells in heterotopic mouse bone marrow transplants after curettage in recipients

Curettage of bone marrow cavities of two bones (femoral and crural) in recipient mice causes a drastic (more than 7-fold) increase in the count of stromal precursor cells in heterotopic bone marrow transplants. Stromal colonies in cell cultures from these transplants consist of fibroblasts with an appreciable admixture of macrophages. All Y chromosome-typed colonies from cultures of female donor bone marrow transplants in recipient males (intact and subjected to curettage) contained cells carrying and not carrying Y chromosome. Quantitative results of Y chromosome typing of cells from colonies corresponded to the fibroblast/macrophage ratio in colonies and the predominant localization of the label corresponded to predominant localization of macrophages (at the periphery of colonies). The results indicate that the pool of bone marrow stromal precursor cells under conditions of increased demands originates from local sources, which confirms ample data on inability of these cells to migration. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 143, No. 5, pp. 568–567, May, 2007