title: Alterations in nociception and body temperature after intracisternal administration of neurotensin, beta-endorphin, other endogenous peptides, and morphine.
abstract: The antinociceptive and hypothermic effects of intracisternal administration of 11 endogenous neuropeptides and morphine were evaluated in mice. Of the substances tested, only neurotensin (NT) and beta-endorphin exerted significant antinociceptive and hypothermic effects; NT was the most potent in inducing hypothermia whereas beta-endorphin was the most potent antinociceptive agent via this route of administration. Both NT, and beta-endorphin were, on a molar basis, considerably more potent antinociceptive agents than morphine, [Met]enkephalin, or [Leu]enkephalin. NT-induced analgesia and hypothermia both were significantly dose-dependent. Substance P was found to produce significant hyperalgesia and hyperthermia. Bombesin produced a significant hypothermic effect, whereas somatostatin and luteinizing hormone-releasing hormone (luliberin) produced hyperthermia. None of the other peptides studies [bradykinin, thyrotropin-releasing factor (thyroliberin), melanocyte-stimulating hormone release-inhibiting factor (melanostatin), somatostatin, [Met]enkephalin, and [Leu]enkephalin] produced any significant alterations in colonic temperature or response to a noxious stimulus with the doses tested. These data demonstrate that NT and beta-endorphin, two endogenous brain peptides, are potent in inducing hypothermia and in producing an antinociceptive state.
mesh_terms: D000818:Animals; D001831:Body Temperature / Q000187:drug effects; D001833:Body Temperature Regulation / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004723:Endorphins / Q000494:pharmacology*; D004745:Enkephalins / Q000494:pharmacology*; D006728:Hormones / Q000494:pharmacology; D008297:Male; D051379:Mice; D009020:Morphine / Q000494:pharmacology*; D009496:Neurotensin / Q000494:pharmacology*; D010146:Pain; D010455:Peptides / Q000494:pharmacology*; D013329:Structure-Activity Relationship
chemical_list: D004723:Endorphins; D004745:Enkephalins; D006728:Hormones; D010455:Peptides; D009496:Neurotensin; D009020:Morphine