[Effects of benzo(a)pyrene exposure on oxidative stress and ATPase in the hippocampus of rats].
OBJECTIVE
To investigate the effects of benzo[a]pyrene (B[a]P) exposure on the behaviors and hippocampal oxidative stress and ATPase in rats and the molecular mechanism of neurobehavioral toxicity of B[a]P.


METHODS
A total of 120 male SD rats (21 days old) were randomly and equally assigned to five groups: blank control group, vegetable oil (solvent control) group, and 2.5, 5, and 10 mg/kg B[a]P exposure groups. The rats in B[a]P exposure groups were injected intraperitoneally with B[a]P once a day for 4 consecutive weeks. Then, Morris water maze and shuttle box were used to evaluate the learning and memory abilities of rats; colorimetric assay was used to measure the activities of superoxide dismutase (SOD), Na(+)/K(+)-ATPase, and Ca(2+)/Mg(2+)-ATPase and the content of malonaldehyde (MDA) in the hippocampus; the concentration of Ca(2+) in the hippocampus was measured by fluorescent labeling.


RESULTS
Compared with the blank control group and solvent control group, the B[a]P exposure groups exhibited significant increases in escape latency, active avoidance response latency, and passive avoidance response latency and significant decreases in number of platform crossings and active avoidance response frequency in the last test (P < 0.05 for all comparisons), with a dose-effect relationship. In addition, the B[a]P exposure groups had significantly lower activities of SOD, Na(+)/K(+)-AT-Pase, and Ca(2+)/Mg(2+)-ATPase and significantly higher MDA level and Ca(2+) concentration than the blank control group and solvent control group (P < 0.05 for all comparisons), with a dose-effect relationship.


CONCLUSIONS
The neurobehavioral toxicity of B[a]P may be related to increased oxidative stress and decreased activities of Na(+)/K(+)-ATPase and Ca(2+)/Mg(2+)-ATPase in the hippocampus of rats.
Department of Occupational and Environmental Medicine, Chongqing medical university, Chongqing 400016, China.
Li
L
Duan
Yan
Y
Tang
Cheng-zhi
CZ
Chen
Bin
B
Pen
Chong-ying
CY
Qiu
You-bin
YB
Qi
Bai-jie
BJ
Tu
D000818:Animals; D001564:Benzo(a)pyrene / Q000633:toxicity*; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism
D001564:Benzo(a)pyrene; D013482:Superoxide Dismutase; D017301:Ca(2+) Mg(2+)-ATPase; D000254:Sodium-Potassium-Exchanging ATPase