Perindopril improves the recovery of bone marrow cells and hematopoietic progenitor cells following sublethal irradiation. B6D2F1 mice (n = 30) received a single dose of 7 Gy and received placebo or perindopril (30 or 90 mg/kg). In each experiment, mice (n = 3) were killed at different times and bone marrow was collected and pooled to perform colony assays. Results are expressed as the percentage of increase for these 2 parameters compared with irradiated mice. Cell counts in irradiated mice and perindopril-treated mice were compared using Student t test. Total cell counts (A; P < .001), CFU-GM counts (B; P < .001), CFU-MK counts (C; P < .01), and BFU-E counts (D; P < .02) were significantly higher in perindopril-treated irradiated mice than in placebo-treated irradiated mice. BMCs indicates bone marrow cells. Error bars represent SD.