Are neuropeptides FF and SF neurotransmitters in the rat?
We have compared the affinities and anti-opioid activities of the different peptides putatively produced by the rat NPFF precursor, NPAFLFQPQRF-NH(2) (NPA-NPFF) and EFWSLAAPQRF-NH(2) (EFW-NPSF), with those already identified in nervous tissue, FLFQPQRF-NH(2) (NPFF) and SLAAPQRF-NH(2) (NPSF). NPFF and NPA-NPFF exhibit a high affinity (0.34 and 0.14 nM, respectively) for [(125)I]1DMe binding sites of the rat spinal cord. In contrast, EFW-NPSF displays an affinity 13 times higher than NPSF (1.99 and 9.5 nM, respectively). In rat dorsal raphe neurones, EFW-NPSF, NPFF, and NPA-NPFF maximally reduce the inhibitory effect of nociceptin on the [Ca(2+)](i) transients triggered by depolarization by 39, 31, and 58%, respectively. NPSF is inactive in the same test. We conclude that NPA-NPFF and EFW-NPSF are likely to be the physiologically active neurotransmitters in rat brain.
Roumy
M
M
Institut de Pharmacologie et de Biologie Structurale, C.N.R.S. UMR 5089, 205 Route de Narbonne, Toulouse Cedex, 31077, France.
Gouardères
C
C
Mazarguil
H
H
Zajac
J M
JM
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism; D006801:Humans; D007457:Iodine Radioisotopes; D008969:Molecular Sequence Data; D009292:Narcotic Antagonists / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D009479:Neuropeptides / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D018377:Neurotransmitter Agents / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D009842:Oligopeptides / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D018847:Opioid Peptides / Q000037:antagonists & inhibitors / Q000494:pharmacology; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D010455:Peptides / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D011485:Protein Binding; D011498:Protein Precursors / Q000737:chemistry / Q000378:metabolism; D051381:Rats; D017386:Sequence Homology, Amino Acid; D013116:Spinal Cord / Q000166:cytology / Q000378:metabolism; D013816:Thermodynamics; D000097629:Nociceptin
D002118:Calcium; D007457:Iodine Radioisotopes; D009292:Narcotic Antagonists; D009479:Neuropeptides; D018377:Neurotransmitter Agents; D009842:Oligopeptides; D018847:Opioid Peptides; D010446:Peptide Fragments; D010455:Peptides; D011498:Protein Precursors; D000097629:Nociceptin; C511785:glutamyl-phenylalanyl-tryptophyl-seryl-leucyl-alanyl-alanyl-prolyl-glutaminyl-arginyl-phenylalaninamide; C414382:neuropeptide SF; C080757:tyrosyl-leucyl-N-methylphenylalanyl-glutaminyl-prolyl-glutaminyl-arginyl-phenylalaninamide; C053651:phenylalanyl-leucyl-phenylalanyl-glutaminyl-prolyl-glutaminyl-arginyl-phenylalaninamide