Spinal antinociception by Tyr-D-Ser(otbu)-Gly-Phe-Leu-Thr, a selective delta-opioid receptor agonist.
The spinal antinociceptive potency of the delta-opioid receptor agonist, Tyr-D-Ser(otbu)-Gly-Phe-Leu-Thr (DSTBULET), was studied in rats. The tail flick test was used as nociceptive stimulus and the rotarod test was used to detect any motor or sedative effects. A dose-response curve was also made for the mu-opioid receptor agonist, morphine. The ED50 for DSTBULET was 0.3 micrograms (0.4 nmol) and a near 100% maximum effect was achieved with 5 micrograms (7.5 nmol). No motor or sedative effects were detected. Antinociception by DSTBULET was antagonized by s.c. naltrindole (1 mg/kg), a selective delta-opioid receptor antagonist, and naloxone (1 mg/kg), a non-selective opioid receptor antagonist. The ED50 for morphine was 0.5 micrograms (1.0 nmol) and the antinociceptive effects were not antagonized by naltrindole (1 mg/kg). The results evidence further the important role of the delta-opioid receptor in spinal nociceptive processing.
Kalso
E A
EA
Nuffield Department of Anaesthetics, University of Oxford, UK.
Sullivan
A F
AF
McQuay
H J
HJ
Dickenson
A H
AH
D000595:Amino Acid Sequence; D000700:Analgesics / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D007211:Indoles / Q000494:pharmacology; D007278:Injections, Spinal; D008297:Male; D008969:Molecular Sequence Data; D009019:Morphinans / Q000494:pharmacology; D009020:Morphine / Q000494:pharmacology; D009270:Naloxone / Q000494:pharmacology; D009271:Naltrexone / Q000031:analogs & derivatives*; D009292:Narcotic Antagonists / Q000494:pharmacology; D009842:Oligopeptides / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011957:Receptors, Opioid / Q000378:metabolism*; D017465:Receptors, Opioid, delta
D000700:Analgesics; D007211:Indoles; D009019:Morphinans; D009292:Narcotic Antagonists; D009842:Oligopeptides; D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; C054868:tyrosyl-seryl(O-tert-butyl)-glycyl-phenylalanyl-leucyl-threonine; D009270:Naloxone; D009271:Naltrexone; D009020:Morphine; C055382:naltrindole