Modulation of delta opioid-evoked hypothermia in rats by WAY 100635 and fluoxetine.
Delta opioid receptor and 5-hydroxytryptamine (5-HT) interactions in rats were investigated using the endpoint of hypothermia. The intraperitoneal (i.p.) administration of SNC-80, a delta opioid agonist (35 mg/kg, i.p.), produced a significant hypothermia. For combined administration, SNC-80-evoked hypothermia was (1) abolished by pre-treatment with naltrindole (5 mg/kg, i.p.); (2) attenuated by pre-treatment with WAY 100635 (1 mg/kg, s.c.), a 5-HT1A antagonist; and (3) enhanced by pre-treatment with non-hypothermic doses of fluoxetine (2.5, 5 and 10 mg/kg, i.p.). The present data reveal that 5-HT1A receptor activation mediates a significant proportion of the hypothermic response to delta opioid receptor activation and that a 5-HT uptake blockade potentiates delta receptor-induced hypothermia.
Department of Pharmaceutical Sciences, Temple University School of Pharmacy, 3307 North Broad Street, Philadelphia, PA 19140, USA. scott.rawls@temple.edu
Scott M
SM
Rawls
Alan
A
Cowan
D000818:Animals; D001549:Benzamides / Q000494:pharmacology; D001833:Body Temperature Regulation; D005473:Fluoxetine / Q000494:pharmacology*; D007035:Hypothermia / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D010879:Piperazines / Q000494:pharmacology*; D011725:Pyridines / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D044282:Receptor, Serotonin, 5-HT1A / Q000502:physiology*; D017465:Receptors, Opioid, delta / Q000819:agonists / Q000502:physiology*; D058829:Serotonin 5-HT1 Receptor Antagonists; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology*
D001549:Benzamides; D005473:Fluoxetine; D010879:Piperazines; D011725:Pyridines; D044282:Receptor, Serotonin, 5-HT1A; D017465:Receptors, Opioid, delta; D058829:Serotonin 5-HT1 Receptor Antagonists; D017367:Selective Serotonin Reuptake Inhibitors; C088464:4-(alpha-(4-allyl-2,5-dimethyl-1-piperazinyl)-3-methoxybenzyl)-N,N-diethylbenzamide; C090413:N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridinyl)cyclohexanecarboxamide