EFFECTS OF A SINGLE POST-OVULATORY DOSE OF ULIPRISTAL ACETATE (UPA) ON IMPLANTATION IN MICE

GÓMEZ ELÍAS, MATÍAS D.; COHEN, DÉBORA J; CUASNICÚ, PATRICIA S; MAY, MARÍA

Mar del Plata

Congreso; LXIII REUNIÓN ANUAL DE LA SOCIEDAD ARGENTINA DE INVESTIGACIÓN CLÍNICA (SAIC); 2018

Sociedad Argentina de Investigación Clínica

UPA is a selective progesterone receptor modulator used as the most effective emergency contraceptive pill in several countries. Although its primary mode of action is to inhibit or delay ovulation, this effect is limited to its intake before LH peak. Therefore, considering its high effectiveness in humans, it is possible that this drug prevents pregnancy by other mechanisms as well. In this regard, despite previous results in mice discarding effects on gamete transport and interaction, we have recently observed that a single post-ovulatory dose of UPA produces a decrease in the number of mouse developing fetuses. Based on this, the aim of this work was to evaluate potential effects of UPA on embryo-uterine interaction in mice. Females in proestrus stage were caged with male breeders and successful mating was confirmed by the presence of copulatory plug (embryonic day 0.5, E0.5). UPA (40mg/kg) or vehicle (sesame oil) was administered i.p. on day E2.5. Detection of early implantation sites was performed on day E5.5 by injecting i.v. Evans blue dye. Results showed that administration of UPA produced a dramatic decrease in this parameter compared to control (p