Identification and cellular localisation of NPW1 (GPR7) receptors for the novel neuropeptide W-23 by [125I]-NPW radioligand binding and immunocytochemistry.
Using a novel radioligand, we have identified high-affinity binding sites (K(D)=0.44+/-0.13 nM) for the recently discovered peptide, neuropeptide W (NPW), in rat brain. Binding density was highest in the amygdala (B(max)=149.9+/-13.8 fmol/mg protein), thalamic, and hypothalamic nuclei. A similar distribution was observed in mouse brain. We have confirmed the identity of these binding sites as the G-protein-coupled receptor, NPW(1) (previously designated orphan receptor GPR7), using site-directed antisera that revealed receptors were expressed by neuronal cell bodies and processes. Additionally, we have demonstrated the presence of NPW-like immunoreactivity in neuronal cell bodies in areas projecting to the amygdala, such as the dorsal raphe nucleus and ventral tegmental area, providing evidence for an emerging new transmitter system.
Singh
Gurminder
G
Clinical Pharmacology Unit, Addenbrooke's Hospital, University of Cambridge, Level 6, Centre for Clinical Investigation, Box 110, Cambridge CB2 2QQ, UK. gs293@cam.ac.uk
Maguire
Janet J
JJ
Kuc
Rhoda E
RE
Fidock
Mark
M
Davenport
Anthony P
AP
D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000033:anatomy & histology / Q000378:metabolism*; D001923:Brain Chemistry; D007150:Immunohistochemistry / Q000379:methods; D007457:Iodine Radioisotopes; D008297:Male; D009479:Neuropeptides / Q000378:metabolism*; D016376:Oligonucleotides, Antisense / Q000493:pharmacokinetics; D011869:Radioligand Assay / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley; D043562:Receptors, G-Protein-Coupled; D018013:Receptors, Neuropeptide / Q000378:metabolism*; D014018:Tissue Distribution
D007457:Iodine Radioisotopes; D009479:Neuropeptides; C485721:Npbwr1 protein, mouse; C485723:Npbwr1 protein, rat; D016376:Oligonucleotides, Antisense; D043562:Receptors, G-Protein-Coupled; D018013:Receptors, Neuropeptide