Effects of inflammation and Epo injections on erythroblast apoptosis. The proportion of annexin V⁺ cells was measured in each subset of erythroblast in bone marrow (A) and spleen (B). Results are shown for control mice (C), ZIGI mice sacrificed 5 days (Z5), 9 days (Z9), 12 days (Z12), and 17 days (Z17) after zymosan injection, Epo-treated control mice (Epo1 and Epo4), and ZIGI mice treated with Epo (Z9Epo1; Z12Epo4). The 3 stages correspond to early (Ery A), intermediate (Ery B), and late erythroblasts (Ery C). Bars represent mean ± SEM. *P < .04, **P < .005 when each value was compared to control mice (C).