HO-1 inhibition increases the heme-regulatory pool, but does not affect in vitro erythroid colony formation in Th3/⁺mice bone marrow cells. (A) Western blot analysis of ferritin, phosphorylated eIF2α (eIF2α-P), and total eIF2α protein levels in Ter119⁺ cells isolated from the bone marrow of Th3/⁺ mice injected with either PBS or SnPP. Results were normalized to the total levels of eIF2α (n = 3). Bone marrow cells from Wt (n = 3) and Th3/⁺ mice (n = 3) were plated in methylcellulose media supplemented with EPO in the presence or absence of SnPP. (B) Number of BFU-E colonies detected in cultures of bone marrow samples derived from Wt and Th3/⁺ mice. (C) Number of CFU-E colonies detected in cultures of bone marrow samples derived from Wt and Th3/⁺ mice. *P < .05, ***P < .001.