Valverde Granados, OlgaMaldonado, Rafael, 1961-Valjent, EmmanuelZimmer, Anne M.Zimmer, Andreas2012-07-052012-07-052000Valverde O, Maldonado R, Valjent E, Zimmer AM, Zimmer A. Cannabinoid withdrawal syndrome is reduced in pre-proenkephalin knock-out mice. J Neurosci. 2000;20(24):9284-9. DOI: 10.1523/jneurosci.20-24-09284.20000270-6474http://hdl.handle.net/10230/16670The functional interactions between the endogenous cannabinoid and opioid systems were evaluated in pre-proenkephalin-deficient mice. Antinociception induced in the tail-immersion test by acute Delta9-tetrahydrocannabinol was reduced in mutant mice, whereas no difference between genotypes was observed in the effects induced on body temperature, locomotion, or ring catalepsy. During a chronic treatment with Delta9-tetrahydrocannabinol, the development of tolerance to the analgesic responses induced by this compound was slower in mice lacking enkephalin. In addition, cannabinoid withdrawal syndrome, precipitated in Delta9-tetrahydrocannabinol-dependent mice by the injection of SR141716A, was significantly attenuated in mutant mice. These results indicate that the endogenous enkephalinergic system is involved in the antinociceptive responses of Delta9-tetrahydrocannabinol and participates in the expression of cannabinoid abstinence.application/pdfeng© 2000, Society for Neuroscience. The published version is available at: http://www.jneurosci.org/content/20/24/9284Cannabinoides -- Efectes fisiològicsCannabinoides -- ReceptorsDrogoaddicció -- Aspectes molecularsinfo:eu-repo/semantics/articlehttp://dx.doi.org/10.1523/jneurosci.20-24-09284.2000CannabinoidOpioidMiceMutationWithdrawalAddictionToleranceinfo:eu-repo/semantics/openAccess