Caracterización del sistema angioregulatorio DDL4-Notch en cuerpo lúteo (CL) de ratas preñadas

HERNANDEZ, F; IRUSTA, G; PELUFFO, MC; STOUFFER, RL; TESONE, M

Ciudad Autónoma de Buenos Aires

Jornada; X Jornada Anual de la SAB; 2008

SAB (Sociedad Argentina de Biología)

Introduction: Notch family, particularly Delta- like ligand (DLL4) and its receptors Notch1 and 4 were recently identified as novel factors involved in angiogenesis regulation. In healthy adult animals or human beings, physiological angiogenesis is mainly limited to the reproductive system. The ovarian vasculature, particularly that associated with the dominant structures (preovulatory follicle and CL) during the ovarian cycle, is one of the few sites where nonpathological development and regression of blood vessels occurs in the adult Objectives: to evaluate the expression of  Notch ligand DLL4 and Notch receptor 4 in the rat CL during different stages of pregnancy and postpartum. Methodology: CL´s were microdissected for western blot and ovaries were fixed for inmunohistochemistry analysis at specific stages of pregnancy (days 7, 17, 19, 21 of gestation) and postpartum (day 1 and 4). Luteal function was investigated by measuring intraluteal Progesterone (P) levels by RIA. Results: A significant drop in luteal P content was observed by day 21 of pregnancy when luteolysis occurs (day 7: 157.8±10.7 vs. day 21: 49.1±6.7 pg P/ug protein). DLL4 expression peaked on day 7 of pregnancy and significantly decreases on day 21. A significant decrease of Notch receptor 4 was observed in postpartum. Immunostaining of perycites was observed surrounding the CL´s using aSMA antibody. Discusion: These results suggest an important role for the Notch system during progression and luteolysis in pregnancy in the rat CL. Supported by: ANPCYT and CONICET.