Effect of amphetamine and phencyclidine on DNA-binding activities of serum response and dyad symmetry elements

Enhancement of AP-1 DNA-binding activity during amphetamine- and phencyclidine-mediated behaviour in rats

Amphetamine (AMPH) and phencyclidine (PCP) induce a variety of behavioural and synaptic changes in the brain, many of which are believed to involve the regulation of gene expression. In this study, we examined the effects of AMPH (5mg/kg), PCP (5mg/kg) and their combination (5mg/kg each) on rat motor activity as well as on the activation of the AP-1 transcription factor in rat brains. AMPH administration, followed by PCP, led to a statistically significant elevation of locomotor activity. It was found that the behavioural response of rats was more pronounced when the two drugs were administered together. The electrophoretic mobility shift assay (EMSA) revealed a significant increase in AP-1-binding activity after treatments with AMPH, PCP or their combination. Super shift/shift inhibition analysis demonstrated the presence of c-Fos and c-Jun protein families in the transcriptional complex bound to AP-1 sequences. Further, our results suggest that the enhanced behavioural changes after AMPH and PCP administration were associated with increased expression of AP-1 proteins (Fos and Jun) in the cortex, striatum and hippocampus and that their binding to AP-1 sites on the DNA contributes to long-term changes in rat brain.

Motor effects of amphetamine in rats pretreated with either dizocilpine or phencyclidine

The aim of the present study was to examine motor effects of amphetamine (AMPH) in rats pretreated with either dizocilpine (MK-801) or phencyclidine (PCP), and to estimate possible differences in these effects. Our results showed that AMPH increases the duration of motor effects of PCP, while it does not change motor effects of MK-801. These findings may reflect different mechanisms of action of MK-801 and PCP, as well as selective influence of AMPH on metabolism of these drugs.