Depressed response of the erythropoietin-responsive splenic cell population to erythropoietin in acutely protein restricted mice.

The erythroid response to Erythropoietin (EPO) is highly dependent on dietary protein. Its operating mechanism, however, remains unsettled. The mouse spleen is an erythropoietic organ which contains an EPO-responsive cell population that can be easily amplified by administration of the hormone. The present study was performed to determine the effect of a protein-free diet offered freely to mice up to two days after injection of r-Hu EPO (1000mU/200 ul) on the response of the above population. Splenic cell suspensions from control and experimental mice were prepared in microwells containing 400 mU r-Hu EPO and appropriate medium. The response to EPO was evaluated in terms of 3H-thymidine uptake. The results obtained indicate that acutely induced protein restriction suppressed the response of the EPO-responsive splenic cell population to EPO when it was imposed on mice immediately after hormone injection, and suggest the appearance of deficient rates of differentiation of erythropoietic units by protein restriction.