Differential sensitivity to neurotensin-induced hypothermia, but not analgesia, in Fischer and Lewis rats.
Neurotensin (NT) produces behavioral and physiological effects, including analgesia and hypotheria, when administered into the CNS. Fischer and Lewis rats exhibit differential behavioral responses to central NT receptor activation. To further characterize these differences, we assessed central NT-induced analgesia and hypothermia in independent groups of rats from each strain. Fischer and Lewis rats showed a similar dose-orderly analgesic response in a hot-plate test. Such an isosensitivity was not observed for NT-induced hypothermia. Although NT produced a dose-orderly decrease in mean rectal temperature in both strains, the magnitude of the hypothermic response was significantly smaller in Fischer than in Lewis rats. These findings provide further evidence of genetic differences in central neurotensinergeric neurotransmission in these two strains.
Bauco
Pat
P
Centre de Recherche Fernand-Seguin, Hôpital Louis-H. Lafontaine et Département de Psychiatrie, Université de Montréal, Montreal, Québec, Canada H1N 3V2. pbauco@crfs.umontreal.ca
Rompré
Pierre Paul
PP
D000700:Analgesics / Q000494:pharmacology*; D000818:Animals; D001831:Body Temperature / Q000187:drug effects*; D007036:Hypothermia, Induced; D009496:Neurotensin / Q000494:pharmacology*; D051381:Rats; D011916:Rats, Inbred F344; D011917:Rats, Inbred Lew; D013997:Time Factors
D000700:Analgesics; D009496:Neurotensin