Serotonin and opiate involvement in the antinociceptive effect of acetylsalicylic acid.
Acetylsalicylic acid (ASA), 400 mg/kg i.p., displayed antinociceptive activity in both the hot-plate and the formalin test. ASA significantly increased brain serotonin (5-HT) content and reduced the number of 5-HT2 receptors in cortical brain membranes 30 min after drug administration. Pretreatment with naloxone abolished the antinociceptive activity of both ASA and morphine in the hot-plate and formalin tests and prevented the increase in cerebral 5-HT concentration and the reduction in 5-HT2 receptors in cortical membranes induced by ASA. The serum salicylate concentrations were not affected by pretreatment with naloxone. These data indicate a central antinociceptive activity of ASA and suggest that ASA may exert its antinociceptive action through serotonergic and opiatergic pathways.
Pini
L A
LA
Department of Internal Medicine, University of Modena, Italy.
Vitale
G
G
Sandrini
M
M
D018712:Analgesics, Non-Narcotic / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000818:Animals; D001241:Aspirin / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D001522:Behavior, Animal / Q000187:drug effects; D001923:Brain Chemistry / Q000187:drug effects; D004723:Endorphins / Q000502:physiology*; D005557:Formaldehyde; D008297:Male; D008566:Membranes / Q000187:drug effects / Q000378:metabolism; D009043:Motor Activity / Q000187:drug effects; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D010147:Pain Measurement / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D011985:Receptors, Serotonin / Q000187:drug effects / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism / Q000502:physiology*
D018712:Analgesics, Non-Narcotic; D004723:Endorphins; D009292:Narcotic Antagonists; D011985:Receptors, Serotonin; D005557:Formaldehyde; D012701:Serotonin; D009270:Naloxone; D001241:Aspirin