Evidence of a central antinociceptive effect of paracetamol involving spinal 5HT3 receptors.
This study was carried out to determine both the effect of systemic paracetamol on the C-fibre evoked reflex activity, a test sensitive to centrally acting analgesic drugs, and the influence of an intrathecally administered 5HT3 receptor antagonist, tropisetron. Paracetamol (200, 300, 400 mg kg-1, i.v.) dose-dependently decreased (maximal effects -60 +/- 8%) the C-evoked responses for a duration of 90 min (for the lowest dose). This effect was totally suppressed by tropisetron (1 microgram, i.t.). These data confirm previous studies suggesting a central effect of this drug and demonstrate the involvement of a spinal 5HT3 mediated serotonergic mechanism.
Pelissier
T
T
Equipe NPPUA, Laboratoire de Pharmacologie Médicale, Faculté de Médecine, Clermont-Ferrand, France.
Alloui
A
A
Paeile
C
C
Eschalier
A
A
D000082:Acetaminophen / Q000494:pharmacology*; D018712:Analgesics, Non-Narcotic / Q000494:pharmacology*; D000818:Animals; D005069:Evaluation Studies as Topic; D007211:Indoles / Q000494:pharmacology; D008297:Male; D009412:Nerve Fibers / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012018:Reflex / Q000187:drug effects*; D012702:Serotonin Antagonists / Q000494:pharmacology*; D013116:Spinal Cord / Q000187:drug effects*; D000077526:Tropisetron
D018712:Analgesics, Non-Narcotic; D007211:Indoles; D012702:Serotonin Antagonists; D000082:Acetaminophen; D000077526:Tropisetron