Reversal of the antinociceptive effects of intrathecally administered serotonin in the rat by a selective 5-HT3 receptor antagonist.
The ability of the highly selective 5-HT3 receptor antagonist ICS 205-930 (3 alpha-tropanyl-1H-indole-3-carboxylic acid ester) to block the increase in tail flick (TFL) and hot plate latencies (HPL) produced by intrathecally (i.t.) administered serotonin (5-HT) was examined in pargyline pretreated rats. ICS 205-930 (0.1 microgram, i.t.) blocked the ability of 5-HT (200 micrograms) to increase TFL and HPL. Significant hyperalgesia, as measured by a decrease in TFL and HPL compared to saline controls, also resulted from either the coadministration of ICS 205-930 (10 micrograms) and 5-HT (200 micrograms) or from ICS 205-930 (100 micrograms) alone. These data suggest an important role for 5-HT3 receptors in modulating spinal nociceptive responses.
Glaum
S R
SR
Department of Pharmacology, University of Illinois, Chicago 60612.
Proudfit
H K
HK
Anderson
E G
EG
D000818:Animals; D007211:Indoles / Q000494:pharmacology*; D007278:Injections, Spinal; D008297:Male; D009619:Nociceptors / Q000187:drug effects*; D010146:Pain / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology*; D012701:Serotonin / Q000378:metabolism / Q000494:pharmacology*; D013116:Spinal Cord / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology; D000077526:Tropisetron
D007211:Indoles; D011985:Receptors, Serotonin; D012701:Serotonin; D000077526:Tropisetron