INFLUENCE OF HEMATOPOIETIC AND LYMPHOID-C ELLS ON STROMAL CFU(F) COLONY FORMATION IN RABBIT BONE-MARROW CULTURES

Guinea pig and rabbit bone marrow and splenic cells with increasing ce llular density suppress in vitro formation of fibroblast colonies by r abbit bone marrow clonogenic stromal cells. At the same time guinea pi g bone marrow and splenic cells produce a stimulating effect on guinea pig bone marrow CFU(f), but they are inhibited by rabbit splenocytes, although to a lesser extent than rabbit bone marrow CFU(f). Rabbit bl ood platelets stimulate the growth of bone marrow CFU(f) of these anim als. However, introduction into the culture of rabbit bone marrow cell s combined with platelets eliminates the latter's growth-stimulating e ffect on stromal clonogenic cells of rabbit bone marrow. The results o btained have evidenced that guinea pig and rabbit bone marrow and lymp hoid cell populations contain cells both stimulating and inhibiting CF U(f) proliferation, and that CFU(f) of varying animal species have dif ferent sensitivity to growth-stimulating and growth-inhibiting effects .