Antinociceptive and Met-enkephalin releasing effects of tachykinins and substance P fragments.
Substance P (SP), physalaemin, SP4-11, SP5-11 and the SP5-11 analog DiMe-C7 induce an antinociceptive effect in rats after intraventricular administration. Other tachykinins and the N-terminal fragments of SP are inactive. All antinociceptive peptides increase the Met-enkephalin efflux from slices of rat periaqueductal gray matter and their antinociceptive potency is correlated with their capacity to release Met-enkephalin. The results, discussed in the light of current theories on different tachykinin receptors, suggest that the SP-P receptor subtype may be involved in the control of noxious stimulation elicited by SP at supraspinal levels.
D000700:Analgesics; D000818:Animals; D004744:Enkephalin, Methionine / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D009479:Neuropeptides / Q000494:pharmacology*; D010146:Pain / Q000503:physiopathology*; D010446:Peptide Fragments / Q000494:pharmacology; D010487:Periaqueductal Gray / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013373:Substance P / Q000031:analogs & derivatives* / Q000494:pharmacology*; D015320:Tachykinins
D000700:Analgesics; D009479:Neuropeptides; D010446:Peptide Fragments; D015320:Tachykinins; D013373:Substance P; D004744:Enkephalin, Methionine