Immature myeloid cells (Gr1⁺CD11b⁺) were increased in spleen and peripheral blood of VEGF-pump mice. The 8- to 10-week-old Balb/c mice were given a continuous infusion of PBS, rhVEGF-A (50 ng/hr), VEGFR2-sel (KDR-sel, 50 ng/hr), or VEGFR1-sel (Flt-sel, 50 ng/hr) over a period of 28 days. (A) Splenocytes were analyzed by FACS for the expression of Gr1 and CD11b. The representative FACS plots were shown. The first plot is the isotype control. (B) The percentage of Gr1⁺CD11b⁺ cells in spleens. (C) The 8- to 10-week-old Balb/c mice given a continuous infusion of PBS treated with rat IgG or infusions of rhVEGF-A (50 ng/hr) were treated with rat IgG, anti-R1 (MF1), or anti-R2 (DC101), 800 μg every 3 days over a period of 28 days. The percentage of Gr1⁺CD11b⁺ cells in spleens is shown. The data (mean ± standard error of the mean [SEM]; n ≥ 5) are repeated 2 times. (D) Red blood cells from murine peripheral blood were lysed and then Gr1⁺CD11b⁺ cell population was analyzed by FACS. The representative FACS plots are shown. The first plot is the isotype control. (E) The percentage of Gr1⁺CD11b⁺ cells in peripheral blood. All of the other data (mean ± SEM, n ≥ 3) repeat 3 times. *P < .05; **P < .01.