The effects of gestational and lactational exposure to Nonylphenol on c-jun, and c-fos expression and learning and memory in hippocampus of male F rat.

OBJECTIVES

To investigate the effects of Nonylphenol (NP) in pups from dams exposed during gestational and lactational periods on immediate early genes (c-jun, c-fos) in hippocampus and the learning and memory of F1 rats.

MATERIALS AND METHODS

Twenty eight pregnant dams, stratified by pregnancy date, were randomly assigned into 4 groups, which were gavaged with NP at the doses of 50 mg/kg/day, 100 mg/kg/day, 200 mg/kg/day and groundnut oil, respectively. Step-down avoidance test, and learning and memory effects of NP were evaluated on 8-weeks-old pups. The expressions of c-jun and c-fos and the activities of choline acetyltransferase (ChAT) and acetylcholinesterase (AchE) were evaluated in hippocampus of pups.

RESULTS

Compared to the control, reaction time (RT) that pups spent to jump to the platform was longer (=0.02), the number of errors were higher (=0.01), and the step-down latency was shorter in the 200 mg/kg/day NP-treated group (=0.04). Exposure to NP induced a significant reduction in ChAT activity in hippocampus in the 100 (=0.005) and 200 mg/kg/day NP-treated groups (=0.002), whereas exposure to 200 mg/kg/day caused a significant increase in AchE activity (=0.004); a dose-response relationship was revealed between ChAT and AchE activities and NP exposure in the hippocampus of pups (=-0.821, =0.01; =0.757, =0.04). Exposure to NP in the 100 and 200 mg/kg/day NP-treated groups exhibited an increase in number of c-fos and c-jun positive cells.

CONCLUSION

Exposure to NP might negatively affect learning and memory ability in F rats, possibly due to the alterations in the expression of c-jun and c-fos, and ChAT, AchE activities in hippocampus of pups.