Effect Of Benzo(a) Pyrene On Learning And Memory Associated Gene Expression Of Rat

Objective: To study the effect of chronic administration of benzo(a)pyrene on learning and memory associated gene expression in rat and investigate the mechanism of benzo(a)pyrene exposure on learning and memory.Methods: Twenty-seven male SD rats were randomly divided into 90 days and 45 days dose toxin exposure groups and control group, each of 9 rats. The toxin exposure groups were abdominally injected BaP two times per week with the dose of 6.25 mg/kg respectively while same volume solvent (refined vegetable oil) was conducted parallel processing to control group. The toxin treatment lasted for 7-14 weeks. Afterwards, animals were sacrificed and the hippocampus were rapidly dissected and frozen in liquid nitrogen. cDNA microarray were used to screen the differentially expressed genes in the hippocampus of adult rats exposed to chronic administration of benzo(a)pyrene and real-time PCR were used to confirm the results with eight genes:Grin2a, adra1b, Gabra5, Egr2, Accn2, Pmch, Drd2, Grial.Results: (1)547 genes exhibited differential expression between exposure group and vehicle group. The expression of 237 genes was up-regulated and 310 genes was down-regulated. (2) Differentially expressed genes were related to response to stimulus and death, cell communication, cell proliferation, developmental process, biological regulation, metabolic process and so on by bioinformatics analysis. (3) The results of real-time PCR were coincided well with the cDNA microarray datas.