Gonadotropin-inhibitory hormone (GnIH), a newly discovered hypothalamic RFamide peptide, inhibits reproductive activity by decreasing gonadotropin synthesis and release in birds. The gene of the mammalian RFamide-related peptides (RFRP) is orthologous to the GnIH gene. This Rfrp gene gives rise to the two biologically active peptides RFRP-1 (NPSF) and RFRP-3 (NPVF), and i.c.v. injections of RFR...

Physical and psychological stressors suppress hypothalamic-pituitary-gonadal axis activity and sexual behavior and consequently induce reproductive dysfunction. Recently, it has been shown that gonadotropin-inhibitory hormone (GnIH), also called RFamide-related peptide 3 (RFRP) in mammals, which is a potent inhibitory regulator of gonadotropin-releasing hormone (GnRH) and gonadotropin, is invol...

BACKGROUND Puberty onset is a complex, organized biological process with multilevel regulation, and its physiopathological mechanisms are yet to be elucidated. RFRP-3, the mammalian ortholog to gonadotropin-inhibitory hormone, is implicated in inhibiting the synthesis and release of gonadotropin in mammals. However, it is unclear whether RFRP-3 participates in regulating pubertal development. ...

RFamide-related peptide-3 (RFRP-3) [mammalian ortholog to gonadotropin-inhibiting hormone (GnIH)] potently inhibits gonadotropin secretion in mammals. Studies of RFRP-3 immunoreactivity and Rfrp expression (the gene encoding RFRP-3) in mammalian brains have uncovered several possible pathways regulating RFRP-3 neurons, shedding light on their potential role in reproduction and other processes, ...

Gonadotropin-releasing hormone (GnRH) controls the reproductive physiology and behavior of vertebrates by stimulating synthesis and release of gonadotropin from the pituitary gland. In 2000, another hypothalamic neuropeptide, gonadotropin-inhibitory hormone (GnIH), was discovered in quail and found to be an inhibiting factor for gonadotropin release. GnIH homologs are present in the brains of v...

Neuroendocrine mechanisms underlying social inhibition of puberty are not well understood. Here, we use a model exhibiting the most profound case of pubertal suppression among mammals to explore a role for RFamide-related peptide-3 [RFRP-3; mammalian ortholog to gonadotropin-inhibitory hormone (GnIH)] in neuroendocrine control of reproductive development. Naked mole rats (NMRs) live in sizable ...

We tested the hypothesis that the effects of food restriction on behavioral motivation are mediated by one or both of the RFamide peptides, RFamide-related peptide-3 (RFRP-3) and kisspeptin (Kp) in female Syrian hamsters (Mesocricetus auratus). Female hamsters fed ad libitum and given a choice between food and adult male hamsters are highly motivated to visit males instead of food on all four d...

Kisspeptin and RFamide-related peptide-3 (RFRP-3) are known to affect GnRH/luteinizing hormone (LH) in several species, including the rat. It has been hypothesized that GnRH/LH changes during the rat estrous cycle may result from changes in the expression of KiSS1 and RFRP-3 genes. Therefore, the present study investigates KiSS1 and RFRP-3 gene expression at the transcriptional level in the rat...

Seasonal mammals use the photoperiodic variation in the nocturnal production of the pineal hormone melatonin to synchronize their reproductive activity with seasons. In rodents, the (SD) short day profile of melatonin secretion has long been proven to inhibit reproductive activity. Lately, we demonstrated that melatonin regulates the expression of the hypothalamic peptides kisspeptins (Kp) and ...

Secreted frizzled related proteins (sFRP) are regulators of Wnt signaling pathways that play central roles in developmental processes and oncogenesis. Various sFRP genes have been cloned from different tissues and implicated in diverse biological activities. rFrp, the rat homologue of sFRP-4, was initially identified as being upregulated in mutant p53-induced cellular transformation. Here, we r...