Inter- and trans-generational effects of gestational ghrelin imbalance on development and reproduction in the mouse

We have demonstrated that ghrelin (Ghrl) participates in fetal programming, since intragestational hyperghrelinaemia increased pup's growth and a Ghrl-receptor antagonist accelerated offspring's sexual maturation and impaired their adult reproductive function. Now, we aim to analyse if these phenotypic changes (found in F1) also occurred in F2 and/or F3 generations.

We treated mice dams (F0), with 4nmol/animal/day of Ghrl or 6nmol/animal/day of an antagonist [Ant:(d -Lys3)GHRP6] from day 1 of pregnancy until delivery. When F1 female pups reached adulthood, they were paired to obtain F2, and subsequently, F2 females were paired to obtain F3. Parameters evaluated in F2 and F3 pups were: growth, physical development, neurobiological maturation, puberty onset and in adulthood, reproductive function.

The F2 and F3 Ant groups showed a significant increase in litter size. Although no differences were detected in the weight of these pups at birth, in adulthood, they were heavier. At F3, pups from the Ant group showed advanced incisors eruption and eye opening compared to controls. Furthermore, F3 male pups from the Ant group showed earlier testis descent, although in adulthood, these males exhibited reduced sperm concentration in comparison to Ghrl. No differences were detected in F2 or F3 females regarding puberty onset or reproduction.

Some fetal programming effects of Ghrl seen in F1, also appeared transgenerationally. Since many women at reproductive age suffer from conditions with reduced Ghrl levels (i.e. obesity or polycystic ovarian syndrome), these results could be relevant to the health of their descendants.