Abnormal erythroid maturation in mice induced by isoniazid.

Defective arythropoiesis characterizes the sideroblastic anemias. The present studies were undertaken to assess the effects of isoniazid, an inhibitor of heme synthesis, on erythropoietin-induced erythroid maturation in hypertransfused mice. Isoniazid was administered at intervals during a wave of induced erythropoiesis, and the effects were assessed in both the bone marrow and peripheral blood. The data showed that isoniazid interfered with heme synthesis and erythroid maturation. The most inhibitory effect of isoniazid was noted at the intermediate normoblast stage. A transient increase in the reticulocyte nonheme iron pool was also found.