Impact of exogen Ghrelin on early embryo development and implantation in mice.

LUQUE EM; VINCENTI LM; RUIZ RD; FIOL DE CUNEO M; MARTINI AC

San Juan

Congreso; Reunión Anual de la Sociedad de Biología Argentina; 2011

Embryos and endometrium express Ghrelin (Ghr) and its receptor. Our study evaluated the impact of Ghr and/or an antagonist (Ant=(D-Lys3)GHRP-6; 6nmol/animal/día) injection on embryo development and implantation. Adult female mice were injected (sc) from ovulation induction (Exp1) or from Day3 to Day7 of pregnancy (Exp2) with: Ghr1 (2nmol/animal/day), Ghr2 (4nmol/animal/day), Ghr2+Ant, Ant or isotonic solution (Con=control) and sacrificed at 80hs from estimated ovulation (embryos retrieved by uterine flushing) or at Day18 of pregnancy respectively. Exp1 (67-136 oocytes/group): Antagonist enhanced embryos recovery from uterus (65±17%; p<0.05 vs Con 28±11%, Ghr1 23±9% and Ghr2 24±8%) and decreased in vivo fertilization indexes (75%; p<0.05 vs Ghr1 93%, Ghr2 92%). Ghrelin and/or Ant increased embryo degeneration and delayed embryonic development (% blastocytes: Ghr2 41%, Ghr2+Ant 29%, Ant 37%; p<0.05 vs Con 66% and Ghr1 63%). Exp2 (6-9 females/group): Ghrelin and/or Ant increased the % of females with embryonic loss (fewer fetuses than corpora lutea) (Ghr1 33%, Ghr2 83%, Ghr2+Ant 75%, Ant 67%; p<0.05 vs Con 13%) and with fetuses that had stopped growing (Ghr2 67%, Ghr2+Ant 50%, Ant 67%; p<0.05 vs Con 0% and Ghr1 0%). These results suggest a biphasic effect of Ghr in modulating in vivo fertilization, embryo development and migration, and implantation.