DOI 10.1095/biolreprod.111.097147 Equine Luteal Function Regulation May Depend on the Interaction Between Cytokines and Vascular Endothelial Growth Factor: An In Vitro Study1

We hypothesized that cytokines influence luteal angiogenesis in mares, while angiogenic factors themselves can also regulate luteal secretory capacity. Therefore, the purpose of this study was to evaluate the role of cytokines—tumor necrosis factor alpha (TNF), interferon gamma (IFNG) and Fas ligand (FASL)— on in vitro modulation of angiogenic activity and mRNA level of vascular endothelial growth factor A (VEGF), its receptor VEGFR2, thrombospondin 1 (TSP1), and its receptor CD36 in equine corpus luteum (CL) throughout the luteal phase. After treatment, VEGF protein expression was determined in midluteal phase (mid) CL cells. The role of VEGF on regulation of luteal secretory capacity was assessed by progesterone (P 4) an