Visualization of MKs in bone marrow sections from mice treated with VEGF-A₁₆₅, PlGF-2, VEGF-E, or vehicle. Mice were administered either VEGF-A₁₆₅, PlGF-2, VEGF-E (100 μg/kg intraperitoneally), or vehicle (PBS) daily for 4 consecutive days before femurs were excised for bone marrow histology. (A) Representative photomicrograph of bone marrow stained with toluidine blue reveal the distribution of sinusoidal vessels (Sv) and MKs (Mk) from a PBS-treated mouse. (B-C) Higher-power magnification of femurs from PBS-treated mice showing localization of MKs in relation to sinusoidal vessels and the stroma. (D) Representative photomicrograph of bone marrow from VEGF-A₁₆₅–treated mouse reveals a more pronounced localization of MKs to sinusoidal vessels. (E-F) Higher-power confirmation of MK localized directly adjacent to sinusoidal vessels. (G-I) Representative photomicrographs of bone marrow from PlGF-2–treated mouse reveals a similar distribution pattern of MKs adjacent to sinusoidal vessels to that of VEGF-A₁₆₅–treated mice. (J-L) Representative photomicrographs of bone marrow from VEGF-E–treated mouse reveals MKs distributed within the bone marrow stroma, with the occasional MK adjacent to a sinusoidal vessel. (A,D,G,J) Magnification:×40. (B,C,E,F,H,I,K,L) Magnification: ×100. Photomicrographs at ×100 magnification have been turned 90° using Microsoft Powerpoint (to allow photomicrographs to fit inside figure). Bar represents 50 μm.