title: Inhibitory influences of FMRFamide and PLG on stress-induced opioid analgesia and activity.
abstract: The effects of i.c.v. administration of the peptide FMRFamide (Phe-Met-Arg-Phe-NH2), as well as i.p. injections of PLG (Pro-Leu-Gly-NH2) and the opiate antagonist, naloxone, on immobilization-induced analgesia and locomotor activity were examined in CF-1 and C57BL strains of mice. Both naloxone (1.0 mg/kg) and FMRFamide (0.10-1.0 microgram) blocked the experimentally induced analgesia and activity, whereas PLG (0.10-10 mg/kg) suppressed only analgesia. These results indicate that FMRFamide (or FMRFamide-like neuropeptides) and PLG may function as differential antagonists of the behavioral and physiological consequences of endogenous opioid activation.
authors.forename: M
authors.initials: M
authors.lastname: Kavaliers
authors.forename: M
authors.initials: M
authors.lastname: Hirst
mesh_terms: D000818:Animals; D001921:Brain / Q000503:physiopathology*; D004723:Endorphins / Q000502:physiology*; D019835:FMRFamide; D009075:MSH Release-Inhibiting Hormone / Q000031:analogs & derivatives / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009043:Motor Activity / Q000187:drug effects*; D009842:Oligopeptides / Q000494:pharmacology*; D010146:Pain / Q000503:physiopathology*; D012149:Restraint, Physical; D013312:Stress, Physiological / Q000503:physiopathology*
chemical_list: D004723:Endorphins; D009842:Oligopeptides; D019835:FMRFamide; C036930:tyrosyl-prolyl-leucyl-glycinamide; D009075:MSH Release-Inhibiting Hormone