Spinal 5-HT or NA uptake inhibition potentiates supraspinal morphine antinociception in rats.
Spinal injection of the specific uptake inhibitor of 5-hydroxytryptamine (5-HT), citalopram, or of noradrenaline (NA), desipramine, potentiated the antinociception following intracerebroventricular injection of morphine in rats tested on the hot plate. Combined spinal injection of citalopram and desipramine caused a synergistic potentiation. The unselective and less potent inhibitor of both 5-HT and NA uptake, amitriptyline, did not cause potentiation. The results support the suggested involvement of both 5-HT and NA pathways in supraspinal morphine antinociception.
D000639:Amitriptyline / Q000378:metabolism; D000818:Animals; D002490:Central Nervous System / Q000187:drug effects* / Q000378:metabolism; D015283:Citalopram; D003891:Desipramine / Q000378:metabolism; D004357:Drug Synergism; D007276:Injections, Intraventricular; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009434:Neural Pathways / Q000187:drug effects; D009638:Norepinephrine / Q000378:metabolism*; D011437:Propylamines / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism*; D013116:Spinal Cord / Q000378:metabolism
D011437:Propylamines; D015283:Citalopram; D000639:Amitriptyline; D012701:Serotonin; D009020:Morphine; D003891:Desipramine; D009638:Norepinephrine