Objective:To explore the relationship between Benzo（a）pyrene（B[a]P）exposure and the changes of morphology

oxidative stress and ATPase in hippocampus in newly born SD rats

and to examine the molecular mechanism of developmental neurotoxicity caused by B[a]

P. Methods:Forty eight male new born SD rats were randomly assigned to one of the following four groups（n=12/group）:vehicle control group

0.02

0.2

2 mg/kg of B[a]P groups. The rats were given oral dose of B[a]

P once a day for 14 days starting from the fifth day after birth. After infection period

optical slices and electron-microscope slices from brain（cortex

hippocampi

cerebellum and brain stem）were made to observe. The colorimetric technique was used to detect the activity of SOD

MDA

Na+-K+-ATPase and Ca

2+

-Mg

2+

-ATP in hippocampus. Results:Brain tissue damage at various degrees was observed in the B[a]P groups compared with that of control group. SOD content

Na

+

-K

+

-ATPase and Ca

2+

-Mg

2+

-ATPase of B[a]P groups decreased obviously compared with those of control group

and MDA content of B[a]

P groups increased obviously

with statistically significant differences（P

<

0.05）. Conclusion:B[a]P could lead to developmental neurotoxicity of new born SD rats

and the change of oxidative stress

the decreased ATPase may play an important role in B[a]

P-caused developmental neurotoxicity.