Impact of changes in postnatal nutrition on puberty onset and the expression of hypothalamic GnRH and ghrelin.

OBJECTIVES

Ghrelin is an octanoylated peptide hormone with multiple and diverse physiologic functions including an important role in energy homeostasis and reproduction. In this study, the adjustment effects of different postnatal nutritional status on puberty onset and the expression of hypothalamic ghrelin and gonadotrophin-releasing hormone (GnRH) were examined in 1 day-old female Sprague-Dawley rats.

MATERIALS AND

METHODS

Animals were randomly assigned into four groups: overnutrition group (Group O), normal group (Group N, control group), and undernutrition groups (Group U and U2). Western blot analysis and immunohistochemistry were used to analyze the expression of hypothalamic ghrelin and GnRH.

RESULTS

With a low level expression of hypothalamic ghrelin, the appearance of puberty onset and secretion peak of GnRH in Group O was earlier than the other groups.

CONCLUSIONS

Undernutrition delayed puberty onset and the GnRH peak, at the same time, promoted the expression of hypothalamic ghrelin.While, the expression of hypothalamic ghrelin was suppressed at puberty onset.