title: Antinociceptive effect of purine nucleotides.
abstract: The antinociceptive effect of purine nucleotides administered systematically (sc) was determined using the formalin and writhing tests in adult male albino mice. The mechanisms underlying nucleotide-induced antinociception were investigated by preinjecting the animals (sc) with specific antagonists for opioid (naloxone, 1 mg/kg), purinergic P1 (caffeine, 5, 10, of 30 mg/kg); theophylline, 10 mg/kg) or purinergic P2 receptors (suramin, 100 mg/kg; Coomassie blue, 30-300 mg/kg; quinidine, 10 mg/kg). Adenosine, adenosine monophosphate (AMP), diphosphate (ADP) and triphosphate (ATP) caused a reduction in the number of writhes and in the time of licking the formalin-injected paw. Naloxone had no effect on adenosine- or adenine nucleotide-induced antinociception. Caffeine (30 mg/kg) and theophylline (10 mg/kg) reversed the antinociceptive action of adenosine and adenine nucleotide derivatives in both tests. P2 antagonists did not reverse adenine nucleotide-induced antinociception. These results suggest that antinociceptive effect of adenine nucleotides is mediated by adenosine.
authors.affiliation: Departamento de Química, Universidade Federal de Santa Maria, Brasil. cfmello@super.ufsm.br
authors.forename: C F
authors.initials: CF
authors.lastname: Mello
authors.forename: J
authors.initials: J
authors.lastname: Begnini
authors.forename: D D
authors.initials: DD
authors.lastname: De-La-Vega
authors.forename: F P
authors.initials: FP
authors.lastname: Lopes
authors.forename: C C
authors.initials: CC
authors.lastname: Schwartz
authors.forename: R E
authors.initials: RE
authors.lastname: Jimenez-Bernal
authors.forename: R G
authors.initials: RG
authors.lastname: Bellot
authors.forename: R
authors.initials: R
authors.lastname: Frussa-Filho
mesh_terms: D000700:Analgesics / Q000494:pharmacology; D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D008297:Male; D051379:Mice; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D009619:Nociceptors / Q000187:drug effects*; D011685:Purine Nucleotides / Q000494:pharmacology*; D011802:Quinidine / Q000494:pharmacology; D018047:Receptors, Purinergic P1 / Q000187:drug effects; D018048:Receptors, Purinergic P2 / Q000187:drug effects; D012394:Rosaniline Dyes / Q000494:pharmacology; D013498:Suramin / Q000494:pharmacology; D013806:Theophylline / Q000494:pharmacology
chemical_list: D000700:Analgesics; D009292:Narcotic Antagonists; D011685:Purine Nucleotides; D018047:Receptors, Purinergic P1; D018048:Receptors, Purinergic P2; D012394:Rosaniline Dyes; D009270:Naloxone; D002110:Caffeine; D013498:Suramin; C048139:Coomassie blue; D013806:Theophylline; D011802:Quinidine