Effects of repeated exposure to toluene or amphetamine on locomotor activity in rats

This study was performed to find out whether repeated exposure to toluene might lead to behavioural sensitization estimated on the basis of spontaneous locomotor activity of rats in an open field. As a reference compound amphetamine was used. Toluene at a dose of 740 mg/kg was administered orally, amphetamine at a dose of 1 mg/kg was administered intraperitoneally for 7 consecutive days. Fourteen days after the last administration the amphetamine or toluene challenge was made. Spontaneous locomotor activity was assessed on the first and seventh day of the exposure and on the day of toluene or amphetamine challenge. Statistics employed a two-way analysis of variance (ANOVA). The results showed that oral administration of toluene at a dose of 740 mg/kg may induce behavioural sensitization. The response to toluene was weaker than that to reference chemical--amphetamine. The results did not indicate the cross-sensitization between toluene and amphetamine.