Modifications induced by Ghrelin administration during the peri-implantation period on mice reproductive success.

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

Córdoba

Jornada; XII Jornadas de Investigación Científica, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba; 2011

Ghrelin (Ghr) functions as a link between reproduction and energy balance. The presence of its specific receptor has been determined in embryos and decidual endometrium, suggesting a role of the peptide in the implantation process. The aim of our study was to evaluate the effects of Ghr, with or without the co-administration of an antagonist (Ant: 6nmol/animal/día (D-Lys 3) GHRP-6) on female mice reproductive success. Sexually mature Albino Swiss mice were injected (sc) from Day 3 to 7 of pregnancy with: Ghr1 (2nmol/animal/día), Ghr2 (4nmol/animal/día), Ghr2+Ant, Ant or isotonic solution (Con=control) and sacrificed at Day 18 of pregnancy in order to evaluate parameters related to reproductive success. None of the applied treatments modified pregnancy percentages. Ghrelin and/or Ant significantly increased the percentage of females with embryo loss (fewer fetuses than corpora lutea) (TM ± SEM: 33.3% Ghr1 n=9, Ghr2 83.3% n=6, Ghr2+Ant 75% n=8, Ant 66.7% n=6, p<0.05 vs Con 12.5% n=8) and the percentage of females with embryos that stopped growing (Ghr2 66.7% n=6, Ghr2+Ant 50% n=8, Ant 66.7% n=6, p<0.05 vs Con 0% n=8 and Ghr1 0% n=9). Besides, Ghr2 treated females increased lesser their body weight (g) during pregnancy than other treatments (Con n=9: Day7 6.4±1.3; Day14 35.8±4.8; Day18 63.7±8.5 and Ghr2 n=8: Day7 0.5±1.0, Day14 16.7±5.5; Day18 36.6±10.5, p<0.001) which coincides with a decrease, although not significant, in their litter size. In conclusion, our data suggest that, although endogenous Ghr is necessary to optimize embryo implantation, a supra-physiological increase in their concentrations exerts deleterious effects on this process and in embryonic development. Results obtained previously in our laboratory support this hypothesis.