SECRETION OF VASCULAR ENDOTHELIAL GROWTH-FACTOR VASCULAR-PERMEABILITYFACTOR FROM HUMAN LUTEINIZED GRANULOSA-CELLS IS HUMAN CHORIONIC-GONADOTROPIN DEPENDENT

Vascularization is a prominent event during corpus luteum formation, p roviding low density lipoproteins for steroid biosynthesis and enablin g transport of secreted steroids, The process of vascularization is co ntrolled by specific regulators. Vascular endothelial growth factor (V EGF), otherwise named vascular permeability factor (VPF), induces endo thelial cell proliferation as well as angiogenesis in vivo and increas es capillary permeability. Here we report the expression of VEGF/VPF m RNA by cultured human luteinized granulosa cells (GC) for at least 10 days. Without HCG VEGF/VPF expression declined after day 4 and by day 10 was reduced to similar to 30% of the value at day 4. However, after culture in the presence of 1 U/ml human chorionic gonadotrophin (HCG) , expression of VEGF/VPF mRNA by GC was four times greater than contro l experiments by day 10, and increased 100% from day 4 to day 10. Simu ltaneously, HCG supplementation increased VEGF/VPF secretion by GC. Me dium VEGF/VPF on day 3 was 13 pM without and 11 pM with HCG. Medium VE GF/VPF on day 10 was 6 pM without HCG and 29 pM with HCG. These result s suggest that vascularization of the corpus luteum is induced by HCG- mediated effects of VEGF/VPF.