Changes in expression of vascular endothelial growth factor and angiopoietin-1 and-2 in the macaque corpus luteum during the menstrual cycle

To determine the temporal expression of vascular growth factors during the lifespan of the primate corpus luteum, experiments were designed to detect mRNA for vascular endothelial growth factor (VEGF), angiopoietin (Ang)-1 an d Ang-2 and to localize protein expression for VEGF in macaque luteal tissu e during the menstrual cycle. Corpora lutea (n = 3-5/stage) were collected during the early (3-5 days post-luteinizing hormone surge), mid- (6-8 days) , mid-late (10-12 days), and late (14-16 days) luteal phase and at menstrua tion (17-18 days). Reverse transcription-polymerase chain reaction products equated to cDNA for VEGF, Ang-1 and Ang-2 in all corpora lutea. VEGF mRNA levels increased (P < 0.05) from early to mid-luteal phase and declined in the late luteal phase and at menstruation. Immunostaining for VEGF was dete cted in the cytoplasm of steroidogenic luteal cells, with the most intense staining in the early luteal phase. Ang-1 and Ang-2 mRNA expression was low in the early to mid-luteal phase but increased (P < 0.05) at late luteal p hase before declining at menstruation. These data suggest transcriptional c ontrol of VEGF, Ang-1 and Ang-2, as well as post-transcriptional control of VEGF, in macaque corpus luteum. Dynamic expression of angiogenic/angiostat ic factors appears critical for development, maintenance and regression of the luteal microvasculature during the menstrual cycle.