Selective eradication of rat bone marrow erythroid cells by administration of cytosine arabinoside. Observations on resumption phase of erythropoiesis.

The in vivo effect of a single i.p. injection of cytosine arabinoside (250 mg/kg body weight) on the rat bone marrow is reported. Cytosine arabinoside (ara-C), a potent inhibitor of DNA-synthesis, was seen to produce selective necrosis of fast cycling bone marrow erythroblasts. The depleted erythroid marrow is replenished by stem cells which are members of the lymphoid-transitional cells compartment. An indirect correlation between the degree of erythroid cell depletion and the extent of marrow lymphocytosis was noted 6-12 h after the administration of ara-C. At 24-48 h, however, the marrow returned to its normal activity. The rat bone marrow 6-12 h following a single injection of ara-C is suggested as an experimental model for providing stem cells committed to the erythroid line.