title: The new neurokinin 1-sensitive receptor mediates the facilitation by endogenous tachykinins of the NMDA-evoked release of acetylcholine after suppression of dopaminergic transmission in the matrix of the rat striatum.
abstract: Using an in vitro microsuperfusion procedure, the NMDA-evoked release of [3H]ACh was studied after suppression of dopamine (DA) transmission (alpha-methyl-p-tyrosine) in striatal compartments of the rat. The effects of tachykinin neurokinin 1 (NK1) receptor antagonists and the ability of appropriate agonists to counteract the antagonist responses were investigated to determine whether tachykinin NK1 classic, septide-sensitive and/or new NK1-sensitive receptors mediate these regulations. The NK1 antagonists, SR140333, SSR240600, GR205171 but not GR82334 and RP67580 (0.1 and 1 microM) markedly reduced the NMDA (1 mm + D-serine 10 microM)-evoked release of [3H]ACh only in the matrix. These responses unchanged by coapplication with NMDA of NK2 or NK3 agonists, [Lys5,MeLeu9,Nle10]NKA(4-10) or senktide, respectively, were completely counteracted by the selective NK1 agonist, [Pro9]substance P but also by neurokinin A and neuropeptide K (1 nM each). According to the rank order of potency of agonists for counteracting the antagonist responses ([Pro9]substance P, 0.013 nM > neurokinin A, 0.15 nM >> substance P(6-11) 7.7 nM = septide 8.7 nM), the new NK1-sensitive receptors mediate the facilitation by endogenous tachykinins of the NMDA-evoked release of ACh in the matrix, after suppression of DA transmission. Solely the NK1 antagonists having a high affinity for these receptors could be used as indirect anti-cholinergic agents.
mesh_terms: D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D009025:Morpholines / Q000494:pharmacology; D016202:N-Methylaspartate / Q000494:pharmacology*; D064729:Neurokinin-1 Receptor Antagonists; D010446:Peptide Fragments / Q000494:pharmacology; D010477:Perfusion; D010880:Piperidines / Q000494:pharmacology; D011812:Quinuclidines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018040:Receptors, Neurokinin-1 / Q000819:agonists / Q000378:metabolism*; D018041:Receptors, Neurokinin-2 / Q000819:agonists; D018042:Receptors, Neurokinin-3 / Q000819:agonists; D013373:Substance P / Q000031:analogs & derivatives* / Q000494:pharmacology; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology; D015320:Tachykinins / Q000378:metabolism*; D013777:Tetrazoles / Q000494:pharmacology; D019805:alpha-Methyltyrosine / Q000494:pharmacology
chemical_list: C469681:2-(1-(2-(4-(2-(3,5-bis(trifluoromethyl)phenyl)acetyl)-2-(3,4-dichlorophenyl)-2-morpholinyl)ethyl)-4-piperidinyl)-2-methylpropanamide; D009025:Morpholines; D064729:Neurokinin-1 Receptor Antagonists; D010446:Peptide Fragments; D010880:Piperidines; D011812:Quinuclidines; D018040:Receptors, Neurokinin-1; D018041:Receptors, Neurokinin-2; D018042:Receptors, Neurokinin-3; D015320:Tachykinins; D013777:Tetrazoles; C054724:senktide; C085215:SR 140333; D013373:Substance P; D016202:N-Methylaspartate; D019805:alpha-Methyltyrosine; C103207:vofopitant; D000109:Acetylcholine; D004298:Dopamine