OBJECTIVES: Paracetamol is converted to an active metabolite AM404 via fatty acid amide hydrolase (FAAH). The aim of the present study was to ascertain whether a FAAH inhibitor URB597 antagonizes paracetamol analgesic activity (and to asses by this way the role of FAAH in analgesic activity of paracetamol). METHODS: The interaction between a FAAH inhibitor URB597 and paracetamol was investigated in the writhing test in mice using an isobolographic analysis. RESULTS: URB597 or paracetamol alone and in combinations produced dose-dependent antinociceptive effects. ED50 values were estimated for the individual drugs and an isobologram was constructed. The observed ED50 value for the URB57-paracetamol combination was 0.097 (0.062-0.247) mg/kg. This value did not differ significantly from the theoretical additive ED50 value for the URB597-paracetamol combination which was 0.108 (0.059-0.198) mg/kg. Thus, inhibition of FAAH by URB597 was not followed by the lack of analgesic activity in paracetamol. CONCLUSION: The present results suggest that the analgesic activity of paracetamol is not dependent solely on FAAH metabolic conversion to AM404 and that paracetamol exerts analgesic activity also by additional mechanisms. © 2010 Neuroendocrinology Letters.

Effects of URB597, an inhibitor of fatty acid amide hydrolase (FAAH), on analgesic activity of paracetamol.

PALAZZO, Enza;GUIDA, Francesca;LUONGO, Livio;DE NOVELLIS, Vito;MARABESE, Ida;
2010

Abstract

OBJECTIVES: Paracetamol is converted to an active metabolite AM404 via fatty acid amide hydrolase (FAAH). The aim of the present study was to ascertain whether a FAAH inhibitor URB597 antagonizes paracetamol analgesic activity (and to asses by this way the role of FAAH in analgesic activity of paracetamol). METHODS: The interaction between a FAAH inhibitor URB597 and paracetamol was investigated in the writhing test in mice using an isobolographic analysis. RESULTS: URB597 or paracetamol alone and in combinations produced dose-dependent antinociceptive effects. ED50 values were estimated for the individual drugs and an isobologram was constructed. The observed ED50 value for the URB57-paracetamol combination was 0.097 (0.062-0.247) mg/kg. This value did not differ significantly from the theoretical additive ED50 value for the URB597-paracetamol combination which was 0.108 (0.059-0.198) mg/kg. Thus, inhibition of FAAH by URB597 was not followed by the lack of analgesic activity in paracetamol. CONCLUSION: The present results suggest that the analgesic activity of paracetamol is not dependent solely on FAAH metabolic conversion to AM404 and that paracetamol exerts analgesic activity also by additional mechanisms. © 2010 Neuroendocrinology Letters.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11591/163362
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 9
  • ???jsp.display-item.citation.isi??? 8
social impact