Abstract: BACKGROUND AND AIM: To study the effects of dibutyl phthalate (DBP) exposure on learning and memory of the F1 generation rats, as well as the expression of spinophilin gene in the hippocampus. MATERIALS AND METHODS: Pregnant Wistar rats were randomly divided into 3 experimental groups and control group, each treated with 25、75、225 mg/kg DBP or vehicle only(corn oil) by gavage since gestation day 6 to postnatal day 28. The general effects of DBP on the pregnant rats and the offspring were observed. The expression level of spinophilin gene in hippocampus of the 21 day_old male pups was determined by Real Time RT_PCR, and the learning and memory abilities of the one month_old male pups was evaluated through Morris water maze. RESULTS: No overt sign of toxicity was found in the dams, but the male pups in the high dose group showed shortened AGD and tail length(P<0.01). In the water maze test, latency to find a hidden platform was longer in the low dose group than that of control(P<0.05). The pups in the former group also spent less time in the target quadrant in the probe test(P<0.01). Moreover, the expression of spinophilin gene was up_regulated 35.7％ in this group as compared with control(P<0.05). CONCLUSION: In utero and lactational DBP exposure decreased learning and memory of the F1 generation rats, associated with up_regulated spinophilin expression in the hippocampus, suggesting a causal relationship.

Key words: dibutyl phthalate, learning and memory, water maze, spinophilin gene, real time quantitative RT_PCR