PGF and preeclampsia: Increased concentrations of VEGFR-1 (capable of blocking the angiogenic action of VEGF) and the soluble form of this vascular endothelial growth factor, sFlt-1(fms-like tyrosine kinase 1), a potent antagonist of VEGF action, and decreased synthesis of placental growth factor (PlGF) are associated with the predominance of antiangiogenic elements characteristic of preeclampsia [37, 38].