title: Structure-antinociceptive activity studies with neurotensin.
abstract: 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.
mesh_terms: 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
chemical_list: D000700:Analgesics; D010446:Peptide Fragments; D009270:Naloxone; D009496:Neurotensin; D013973:Thyrotropin-Releasing Hormone