Effect of VEGFR1 and VEGFR2 stimulation on MK maturation. Mice were administered either VEGF-A₁₆₅ (100 μg/kg intraperitoneally), PlGF-2, VEGF-E (100 μg/kg intraperitoneally), or vehicle (PBS) each day for 4 consecutive days. (A-B) Representative histograms of CD41⁺ MKs stained with TOPRO-3 revealing respective peaks of increasing DNA ploidy number. (A) CD41⁺ MKs with 2n, and (B) 2n peak subtracted to reveal 4n to 128n. (C) Percentage of bone marrow and splenic MKs with a ploidy number of 16n or greater in mice administered either VEGF-A₁₆₅, PlGF-2, or VEGF-E. (D) Histogram revealing spread of bone marrow MK ploidy above 16n in mice administered either VEGF-A₁₆₅, PlGF-2, or VEGF-E; n = 5-6 animals per group. Data are expressed as mean ± SEM; *P < .05 compared with control.