RT Journal Article
SR Electronic
T1 Neurotensin-induced antinociception in mice: antagonism by thyrotropin-releasing hormone.
JF Journal of Pharmacology and Experimental Therapeutics
JO J Pharmacol Exp Ther
FD American Society for Pharmacology and Experimental Therapeutics
SP 645
OP 651
VO 217
IS 3
A1 A J Osbahr, 3rd
A1 C B Nemeroff
A1 D Luttinger
A1 G A Mason
A1 A J Prange, Jr
YR 1981
UL http://jpet.aspetjournals.org/content/217/3/645.abstract
AB Neurotensin (NT), administered intracisternally to mice, produced significant dose-dependent antinociception in three analgesic tests: tail immersion, hot-plate and acetic acid writhing. Naloxone (1-5 mg/kg), an opiate antagonist administered i.p. 20 min before NT administration, did not significantly alter NT-induced antinociception in any of these tests; naloxone did significantly reverse beta-endorphin-induced antinociception. However, centrally and peripherally administered thyrotropin-releasing hormone antagonized NT-induced (but not beta-endorphin-induced) antinociception. Equimolar doses of another tripeptide (Pro-Leu-Gly-NH2; melanostatin) did not alter the effects of NT. The data obtained in this study confirm NT-induced antinociception, provide further evidence that NT does not activate naloxone-sensitive opiate receptors and demonstrate that this brain effect of NT is antagonized by thyrotropin-releasing hormone. These findings therefore support the hypothesis that NT and thyrotropin-releasing hormone are functional antagonists in the central nervous system.