Ghrelin effects on in vivo fertilization rate and litter size in mice

Abstract

Male sexual behavior is highly regulated by neuroendocrine interactions. Testosterone is a key hormone for male sexual development and sexual behavior. Ghrelin (Ghrl) is a growth hormone secretagogue peptide that is being investigated for its implications on the reproductive system. In previous stidies, our group has demonstrated that Ghrl chronic administration decreases plasma testosterone concentration and affects quality and concentration of sperm. That is why we studied the impact of intrahypothalamic Ghrl treatment on fertilization index in vivo and litter size.

Males were treated for 42 days with cerebrospinal fluid (control) or Ghrl 3.0 nmol/day administered in the hypothalamus and 3 days before the end of treatment, males were housed with untreated females on the afternoon of proestrus and the existence of copulation was analyzed. 18 days after copulation, offspring number and litter size was analyzed. Additionally, reproductive function of treated animals was evaluated in vitro, using untreated females. The data were analyzed by ANOVA followed by an LSD test, N = 6-8 animals / group.

Treatment with Ghrl 3.0 nmol / day significantly increases the percentage of embryonic loss (F = 2.58, df = 2, p <0.05) and the number of atrophied fetuses (F = 2.24, df = 2, p <0.05) in females that copulated with treated animals. Therewere no significant differences between other parameters evaluated (in vivo fertilization rate, number of fetuses / litter size, litter weight, average weight of the offspring, number of corpus lutea). No significant differences were observed in the percentage of oocytes fertilized in vitro in animals treated with Ghrl with respect to control animals (p> 0.05).

Ghrelin treatment did not affect the fertilization rate, however, it produced an increase in the percentage of embryonic loss in vivo