Comparação dos efeitos dos derivados da catinona, metedrona e mefedrona em camundongos : determinação dos efeitos comportamentais e bioquímicos

Abstract

We have compared the behaviour and neurochemical effects of synthetic cathinones mephedrone and methedrone in mice, with attempts to evaluate some the mechanisms of action of methedrone, as well as the influence of nightclub-like stimulation on the behaviour. The effects of cathinone derivatives were examined in a series of behavioural tests in mice, and monoamine brain levels were determined by HPLC. Since there is a correlation between club parties and consume of recreational drugs, separated groups were pre-exposed to nightclub-like environment. Cathinone derivatives caused marked hyperlocomotion, allied to motor coordination inability, through 30 min after injection. Moreover, mephedrone caused anxiolytic-like effects, while methedrone induced anxiogenic actions. Both cathinone derivatives increased the latency in the hot-plate test, with a significant reduction of immobility time in tail suspension test. Mephedrone triggered 2- and 3-fold increase of dopamine and serotonin levels, respectively, in the nucleus accumbens, with 1.5-fold elevation of dopamine contents in the frontal cortex. Methedrone caused a 2-fold increase of dopamine in the nucleus accumbens and striatum, and 1.5-fold increase of serotonin levels in the hippocampus and striatum. Part of methedrone effects appear to be dependent on dopamine and serotonin modulation. Noteworthy, nightclub-like stimulation produced a further increase of latency to thermal stimulation, in both mephedrone and methedrone-treated mice. Mephedrone and methedrone induced a series of distinct behavioural changes likely by modulation of dopamine and serotonin systems. Curiously, increased latency to thermal stimulation elicited by cathinones was intensified by nightclub-like environment.