[Influence of benzo[a]pyrene on learning and memory and content of amino acid neurotransmitters in hippocampus of rats].

Objective: To study the effects of benzo[a]pyrene (B[a]P) on capability of learning and memory and the content of amino acid neurotransmitters in hippocampus of rats.

Methods: Thirty-two healthy, male SD rats were randomly divided into 4 groups according to their weights after intubated into ventricles: the solvent control group, 2.5, 5.0 and 10.0 mmol/L groups. 10 microl of B[a]P olive oil solutions, of different concentrations 2.5, 5.0 and 10.0 mmol/L, were injected into rats' lateral ventricles, respectively. Rats in the solvent control group were injected into the same volume of olive oil as that in B[a]P group. Rats' capability of learning and memory was tested by Morris water maze. The content of amino acid neurotransmitters in rats' hippocampus were determined by high performance liquid chromatogram with a fluorescence detector.

Results: Compared with the controls, the performances of learning and memory of rats decreased significantly in B[a]P treated groups (P<0.01). Levels of glutamate (Glu) were lower significantly in treated groups than that in controls (P<0.01). No significant differences were found in contents of aspartic acid (Asp), glycine (Gly) and aminobutyric acid (GABA) among the four groups.

Conclusion: B[a]P can damage rats' spatial learning and memory, and which could be related to decreased contents of excitatory amino acids in hippocampus.