The effects of ethanol and the role of the spleen during benzene-induced hematotoxicity.

Splenectomized and spleen-bearing mice were used to explore the source of nucleated red blood cells (normoblasts) appearing in the peripheral blood of animals treated with both benzene and ethanol and the role of splenic hematopoiesis in compensating for bone marrow stresses by repeated benzene and ethanol exposure. Regardless of operative status, mice exposed to the combined treatment demonstrated a transient appearance of normoblasts in the peripheral blood. Thus, the marrow is the apparent source of the peripheral normoblasts. This condition was not observed in mice treated with only benzene or with only ethanol. Splenectomy significantly influenced bone marrow response to the hematotoxic effects of benzene alone as well as the combined treatment of benzene and ethanol, as evidenced by altered marrow normoblast and granulocyte equilibria.