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We examined whether corticotropin-releasing factor (CRF) was involved in orexin-induced grooming and face-washing behaviors, and whether orexin was involved in the stress reaction. Administration of alpha-helical CRF, CRF antagonist, alone had no behavioral effect, but it blocked the orexin-induced grooming and face-washing behaviors in rats. The level of(More)
The effect of lateral cerebroventricular injection of the appetite-stimulating neuropeptide, orexin and neuropeptide Y (NPY), on the behavior of rats was investigated. An immediate increase in face washing activity was observed after injection of orexin A or orexin B, but not NPY. Orexin A had a more potent effect on face washing behavior than orexin B.(More)
Bone remodeling, the function affected in osteoporosis, the most common of bone diseases, comprises two phases: bone formation by matrix-producing osteoblasts and bone resorption by osteoclasts. The demonstration that the anorexigenic hormone leptin inhibits bone formation through a hypothalamic relay suggests that other molecules that affect energy(More)
The discovery of neuropeptides has resulted in an increased understanding of novel regulatory mechanisms of certain physiological phenomena. Here we identify a novel neuropeptide of 36 amino-acid residues in rat brain as an endogenous ligand for the orphan G protein-coupled receptor FM-4/TGR-1, which was identified to date as the neuromedin U (NMU)(More)
There are many orphan G protein-coupled receptors (GPCRs), for which ligands have not yet been identified, in both vertebrates and invertebrates, such as Drosophila melanogaster. Identification of their cognate ligands is critical for understanding the function and regulation of such GPCRs. Indeed, the discovery of bioactive peptides that bind GPCRs has(More)
Antisera to orcokinin B, CCHamide 1, and CCHamide 2 recognize enteroendocrine cells in the midgut of the fruitfly Drosophila melanogaster and its larvae. Although the antisera to CCHamide 1 and 2 are mutually cross-reactive, polyclonal mouse antisera raised to the C-terminals of their respective precursors allowed the identification of the two different(More)
Ghrelin was originally isolated from rat stomach as an endogenous ligand for the GH secretagogue receptor. The major active form of ghrelin is a 28-amino acid peptide modified by an n-octanoic acid on the serine 3 residue, and this lipid modification is essential for the biological activity of ghrelin. However, it is not clear whether prohormone convertase(More)
Ghrelin is a peptide hormone in which serine 3 is modified by n-octanoic acid through GOAT (ghrelin O-acyltransferase). However, the enzymological properties of GOAT remain to be elucidated. We analyzed the in vitro activity of GOAT using the recombinant enzyme. Unexpectedly, although the main active form of ghrelin is modified by n-octanoic acid, GOAT had(More)
Orexin (hypocretin) is a peptide that has been found to stimulate food intake in rats. However, we have recently demonstrated that orexin stimulates the release of corticotropin releasing hormone (CRF) which has been known to decrease the food intake. Therefore, we examined the mechanism of effect of orexin on food intake. Although the other appetite(More)
Ghrelin, a 28-amino-acid peptide, has recently been isolated from the rat stomach as an endogenous ligand for the GH secretagogue receptor. We have reported previously that central or peripheral administration of ghrelin stimulates food intake, and the secretion of GH and gastric acid in rats. In the present study, we investigated how much endogenous(More)