Fig. 4.

Survival curves for lethally irradiated BALB/c mice after transplantation with murine HSPCs, which had been left untreated, treated with the combination of treprostinil and forskolin and further stimulated by in vivo administration of treprostinil. Murine HSPCs were incubated in the absence (no treatment; n = 9) or presence of the combination of 10 μM treprostinil and 30 μM forskolin (in vitro pretreatment); subsequently, the cell suspension (3 × 10⁵ cells per mouse) was administered by tail vein injection to lethally irradiated recipient mice. Some mice, which received pretreated cells, were also treated in vivo with treprostinil (in vitro and in vivo treatment; n = 10; 0.15 mg kg⁻¹ s.c for 10 days), whereas others received no further treatment (in vitro pretreatment; n = 13). The differences between the survival curves are statistically significant: in vitro pretreatment versus in vitro/in vivo treatment, P = 0.01290; untreated control versus in vitro/in vivo treatment, P = 0.0003 (log-rank test).