Antinociceptive cross-tolerance between [D-Arg2]-dermorphin tetrapeptide analogs and morphine.
Cross-tolerance between [D-Arg2]-dermorphin tetrapeptide analogs and morphine with respect to antinociception was examined in the present set of experiments. Systemic administration of H-Tyr-D-Arg-Phe-Gly-NH2 (TDAPG-NH2), H-Tyr-D-Arg-Phe-beta-Ala-OH (TDAPA) or morphine over a period of 5 days produced the development of tolerance. In the cross-tolerance study, antinociception after subcutaneous (SC), intracerebroventricular (ICV) and intrathecal (IT) administrations of TDAPG-NH2 and TDAPA in morphine-tolerant mice was not significantly different from their respective effects in saline-pretreated control mice. A marked tolerance to SC- and ICV-administered morphine was seen in mice made tolerant to TDAPG-NH2 and TDAPA. However, IT administration of morphine produced no significant decrement in the antinociceptive activity in mice made tolerant to TDAPG-NH2 and TDAPA. These data indicate that [D-Arg2]-dermorphin tetrapeptide analogs can produce significant antinociception in morphine-tolerant mice.
Chaki
K
K
Department of Pharmacology, Tohoku College of Pharmacy, Sendai, Japan.
Sakurada
S
S
Sakurada
T
T
Nakata
N
N
Kisara
K
K
Watanabe
H
H
Suzuki
K
K
D000595:Amino Acid Sequence; D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D004361:Drug Tolerance; D007276:Injections, Intraventricular; D007279:Injections, Subcutaneous; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D009020:Morphine / Q000494:pharmacology*; D009842:Oligopeptides / Q000494:pharmacology*
D000701:Analgesics, Opioid; D009842:Oligopeptides; C059393:tyrosyl-arginyl-phenylalanyl-glycinamide; D009020:Morphine; C059394:tyrosyl-arginyl-phenylalanyl-alanine; C045484:dermorphin, Arg(2)-