Effect of ECC-derived sFlt-1 on HUVEC proliferation. HUVECs (2 × 103 cells) were cultured alone or in the presence of 10 ng VEGF, 10 μl of plasma collected at T2 during ECC and/or 0.25 μg rabbit anti-soluble Flt-1. A: Cell proliferation (in sixplicates) was measured by a colorimetric method. One representative experiment out of 3 is shown. B: Cell number (in quadruplicate) was determined by direct cell counts. One representative experiment out of 2 is shown. Statistical differences were made using the Mann-Whitney U-test.