LACK OF ACTIVITY OF AZAPROPAZONE IN THE HOT-PLATE TEST AND IN 5-HT1A AND 5-HT2 RECEPTOR SUBTYPES IN RAT-BRAIN MEMBRANES

This study aimed to investigate the antinociceptive activity of azapro pazone (AZA), a weak prostaglandin synthesis inhibitor using the hot-p late test, and its ability to modify the serotonin-binding capacity in rat brain membranes. it revealed that AZA had no antinociceptive effe ct in the hot-plate test at the doses of 400 and 600 mg/kg when orally administered (p.o.), and at 400, 500 and 600 mg/kg after intraperiton eal injection (i.p.). At the dose of 600 mg/kg i.p. the drug failed to modify the number and the affinity of 5-HT1A and 5-HT2 receptors in r at brain membranes. in accordance with our previous findings on a posi tive correlation between NSAIDs antinociception in this experimental m odel and changes in 5-HT receptor characteristics, these results sugge st an association between the lack of AZA-mediated antinociception in the hot-plate test and the drug's inability to modify the characterist ics of 5-HT1A and 5-HT2 receptor binding sites in rat brain membranes.