Stimulatory effect of substance P on the spontaneous release of newly synthesized [3H]dopamine from rat striatal slices: a tetrodotoxin-sensitive process.
Striatal slices from the rat were continuously superfused with [3H]tyrosine in order to estimate the release of newly synthesized [3H]dopamine [( 3H]DA). Substance P (SP) and neuromedin K (NKB) stimulated the spontaneous release of [3H]DA when used in concentrations (from 10(-9) M to 10(-7) M). The stimulatory effect of substance P (10(-8) M) was prevented completely when slices were superfused with tetrodotoxin (10(-7) M) or the substance P antagonist (D-Arg1,D-Pro2,D-Trp7,9,Leu11) substance P (10(-5 M) indicating that the response evoked by substance P was mediated by substance P receptors but that these were not located on DA nerve terminals. In addition, substance P did not modify the stimulatory effect of acetylcholine (ACh) (10(-5) M) on the spontaneous release of [3H]DA since the effects of substance P (10(-7) M) and ACh (10(-5) M) were additive.
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D004298:Dopamine / Q000096:biosynthesis / Q000378:metabolism*; D004357:Drug Synergism; D008297:Male; D015287:Neurokinin B; D009479:Neuropeptides / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011994:Recombinant Proteins; D013373:Substance P / Q000031:analogs & derivatives / Q000494:pharmacology*; D013779:Tetrodotoxin / Q000494:pharmacology*
D009479:Neuropeptides; D011994:Recombinant Proteins; D013373:Substance P; D013779:Tetrodotoxin; C050702:substance P, Arg(1)-Pro(2)-Trp(7,9)-Leu(11)-; D015287:Neurokinin B; D000109:Acetylcholine; D004298:Dopamine