Thrombocytopoietic activity of rhTPO, rhIL-11, and JTZ-132 in myelosuppressed mice induced by x-ray irradiation. Changes of platelet (A,D), WBC (B,E), and RBC (C,F) numbers in mice that received 5 Gy irradiation using a soft x-ray ionization chamber at day 0. (A-C) Vehicle for rhTPO and rhIL-11 (0.1% BSA/saline; ○), rhTPO (1 μg/mouse/day, •), or rhIL-11 (10 μg/mouse/day, ▴), and (D-F) vehicle for JTZ-132 (30% polyethylene glycol-400/7% hydroxypropyl β-cyclodextrin, ○) or JTZ-132 (3 mg/kg/day, •; 9 mg/kg/day, ▴; 30 mg/kg/day, ▪) were dosed subcutaneously from days 1 to 4. Heparinized blood was obtained from the sinus vein of the mice at indicated days, and immediately measured the blood cell count by Sysmex F-800. Data represent mean ± SEM of 8 mice. Statistical analysis was performed by Student t test (# indicates P < .05; ##, P < .01) or Dunnett test (*indicates P < .05; **, P < .01) versus corresponding vehicle treatment.