Secretion of vascular endothelial growth factor/vascular permeability factor from human luteinized granulosa cells is human chorionic gonadotrophin dependent

Vascularization is a prominent event during corpus luteum formation,providing low density lipoproteins for steroid biosynthesis and enablingtransport of secreted steroids. The process of vascularization iscontrolled by specific regulators. Vascular endothelial growth factor(VEGF), otherwise named vascular permeability factor (VPF), inducesendothelial cell proliferation as well as angiogenesis in vivo andincreases capillary permeability. Here we report the expression of VEGF/VPFmRNA by cultured human luteinized granulosa cells (GC) for at least 10days. Without HCG VEGF/VPF expression declined after day 4 and by day 10was reduced to approximately 30% of the value at day 4. However, afterculture in the presence of 1 U/ml human chorionic gonadotrophin (HCG),expression of VEGF/VPF mRNA by GC was four times greater than controlexperiments by day 10, and increased 100% from day 4 to day 10.Simultaneously, HCG supplementation increased VEGF/VPF secretion by GC.Medium VEGF/VPF on day 3 was 13 pM without and 11 pM with HCG. MediumVEGF/VPF on day 10 was 6 pM without HCG and 29 pM with HCG. These resultssuggest that vascularization of the corpus luteum is induced byHCG-mediated effects of VEGF/VPF.