Capacity Building and Industrialization Projects (2014-2573).

The mammalian gonadotropin-inhibitory hormone (GnIH) ortholog, RFamide-related peptide (RFRP) is considered to act on gonadotropin-releasing hormone (GnRH) neurons and the pituitary to inhibit gonadotropin synthesis and release. However, there is little evidence documenting whether RFamide-related peptide 3 (RFRP-3) played a primary role in inhibition of the hypothalamo-pituitary-gonadal (HPG) axis prior to the onset of puberty. The present study aimed to understand the functional significance of the neuropeptide on pubertal development. The developmental changes in reproductive-related gene expression at mRNA level were investigated in the hypothalamus of female mice. The results indicated that RFRP-3 may be an endogenous inhibitory factor for the activation of the HPG axis prior to the onset of puberty. In addition, centrally-administered RFRP-3 significantly suppressed plasma luteinizing hormone (LH) levels in prepubertal female mice. Surprisingly, centrally-administered RFRP-3 had no effects on plasma LH levels in ovariectomized (OVX) prepubescent female mice. In contrast, RFRP-3 also inhibited plasma LH levels in OVX prepubescent female mice, which were treated with 17β-estradiol replacement. Our study also examined the effects of RFRP-3 on plasma L