title: Modulation of neuropeptide FF release from rat spinal cord slices by glutamate. Involvement of NMDA receptors.
abstract: This study examined the effects of glutamate receptor agonists on the release of neuropeptide FF-like immunoreactivity from rat spinal dorsal half slices. Glutamate (10 microM) only induced release in Mg(2+)-free medium enriched with glycine (1 microM) and with slight depolarization (15 mM K+). This effect was abolished by the NMDA receptor antagonist, 2-amino-5-phosphonovalerate (100 microM), suggesting major participation of NMDA receptors. The quisqualate and metabotropic receptor agonists, alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) and trans-1-hydroxy-5-methylisoxazole-4-propionate (t-ACPD) respectively, had no effect at 10 microM. In contrast, NMDA dose dependently stimulated neuropeptide FF release, even in the presence of the Na+ channel blocker, tetrodotoxin (1 microM), suggesting that NMDA receptors involved in the release of neuropeptide FF are mainly located on nerve terminals. The NMDA receptor antagonists, 2-amino-5-phosphonovalerate or (+)-5-methyl-10-11-dihydro-5H-dibenzo [a,d]cyclohepten-5,10-imine (MK-801) (100 microM), blocked the 10 microM NMDA effect. Furthermore, neuropeptide FF-like material inhibited binding of [125I]Y8Fa, a radioiodinated analog of neuropeptide FF, to spinal membranes, suggesting physiological relevance of NMDA-induced release. Taken together, these results suggest a relationship between neuropeptide FF and NMDA receptors in the spinal cord.
authors.affiliation: INSERM U. 259, Université de Bordeaux II, France.
authors.forename: J P
authors.initials: JP
authors.lastname: Devillers
authors.forename: G
authors.initials: G
authors.lastname: Simonnet
mesh_terms: D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000818:Animals; D003515:Cycloleucine / Q000031:analogs & derivatives / Q000494:pharmacology; D016291:Dizocilpine Maleate / Q000494:pharmacology; D018698:Glutamic Acid / Q000494:pharmacology*; D066298:In Vitro Techniques; D007457:Iodine Radioisotopes; D008297:Male; D008566:Membranes / Q000187:drug effects / Q000378:metabolism; D016202:N-Methylaspartate / Q000494:pharmacology; D009479:Neuropeptides / Q000378:metabolism*; D009498:Neurotoxins / Q000494:pharmacology; D009842:Oligopeptides / Q000378:metabolism*; D011863:Radioimmunoassay; D011869:Radioligand Assay; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects / Q000378:metabolism*; D013116:Spinal Cord / Q000187:drug effects / Q000378:metabolism*; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000494:pharmacology
chemical_list: D007457:Iodine Radioisotopes; D009479:Neuropeptides; D009498:Neurotoxins; D009842:Oligopeptides; D016194:Receptors, N-Methyl-D-Aspartate; D003515:Cycloleucine; C036361:1-amino-1,3-dicarboxycyclopentane; D018698:Glutamic Acid; D016202:N-Methylaspartate; D016291:Dizocilpine Maleate; D015763:2-Amino-5-phosphonovalerate; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; C053651:phenylalanyl-leucyl-phenylalanyl-glutaminyl-prolyl-glutaminyl-arginyl-phenylalaninamide