Structure-antinociceptive activity studies with neurotensin.
The antinociceptive effects of synthetic neurotensin (NT), its fragments and analogues administered into the lateral cerebroventricle have been compared in the conscious mouse. Intracerebroventricular (i.c.v.) administration of NT produced a dose-dependent antinociceptive effect in the tail pressure test. The NT fragments and analogues, NT(8-13), NT(8-10), NT(9-13), NT(9-11), NT(8-11) NHEt and NT(9-11) NHEt were also effective antinociceptive peptides. The potency of NT(8-13) and the duration of its effects were found to be approximately equal to those of NT. The antinociceptive effects produced by NT, NT(8-13) and NT(9-13) were significantly reversed by the opioid antagonist naloxone but not by thyrotropin releasing hormone. It is concluded that NT(8-13) is required for the full expression of the antinociceptive effects of NT which may be mediated in part through the brain opioid system.
D000700:Analgesics; D000818:Animals; D007276:Injections, Intraventricular; D008297:Male; D051379:Mice; D009270:Naloxone / Q000494:pharmacology; D009496:Neurotensin / Q000031:analogs & derivatives / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology; D013329:Structure-Activity Relationship; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology; D013997:Time Factors
D000700:Analgesics; D010446:Peptide Fragments; D009270:Naloxone; D009496:Neurotensin; D013973:Thyrotropin-Releasing Hormone