Background: Comparison of the effect of lactation on expression of RFRP-3 mRNA in dorsomedial hypothalamic nucleus (DMH) and KiSS-1 mRNA in arcuate nucleus (ARC) of hypothalamus in lactating and nonlactating rat Materials and Methods: Fourteen rats of the Sprague- Dawley strain were randomly allotted into three groups. The non-lactating rats (n=5) were separated from their pups immediately upon...

Background RFamide-related peptide-3 (RFRP-3) inhibits gonadotropin releasing hormone (GnRH) and luteinizing hormone (LH) secretion in rats. This study evaluates the effects of litter size and suckling intensity on RFRP mRNA expression in the dorsomedial hypothalamic nucleus (DMH) of rats. MaterialsAndMethods A total of 32 pregnant and 4 non-lactating ovariectomized (control group) Sprague-Dawl...

BACKGROUND RFamide-related peptide-3 (RFRP-3) inhibits gonadotropin releasing hormone (GnRH) and luteinizing hormone (LH) secretion in rats. This study evaluates the effects of litter size and suckling intensity on RFRP mRNA expression in the dorsomedial hypothalamic nucleus (DMH) of rats. MATERIALS AND METHODS A total of 32 pregnant and 4 non-lactating ovariectomized (control group) Sprague-...

Introduction: Arginine-phenylalanine-amide-related peptide-3 (RFRP-3) is an inhibitor of gonadotropin releasing hormone (GnRH) secretion and an appetizer. Kisspeptin is a stimulator of GnRH and a regulator of energy metabolism. The objectives of the present study were to compare the effect of long term malnutrition on expression of RFRP-3 mRNA in dorsomedial hypothalamic nucleus (DMH) and KiSS-...

Jerboas are wild rodents exhibiting exceptional adaptation to their desert environment. Under harsh autumn conditions, they shut down reproduction, increase body weight and hibernate, while during spring they become sexually active even under negative energy-balance. We recently reported that these rhythms are associated with synchronized changes in genes expressing reproductive (Kiss1, Rfrp) a...

The existence of a hypothalamic gonadotropin-inhibiting system has been elusive. A neuropeptide named gonadotropin-inhibitory hormone (GnIH, SIKPSAYLPLRF-NH(2)) which directly inhibits gonadotropin synthesis and release from the pituitary was recently identified in quail hypothalamus. Here we identify GnIH homologs in the human hypothalamus and characterize their distribution and biological act...

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...

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...

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, ...