Expression of multidrug resistance associated protein 1 mRNA in the brain of chronic epileptic rats

Objective The pathogenesis of refractory epilepsy(RE) is not yet understood.Multidrug resistance associated protein 1(MRP1) has been shown to correlate with the resistance to some anticancer drugs.Does MRP1 also play a role in the resistance to antiepileptic drugs? The aim of this study is to investigate the influence of spontaneous seizures,Levetiracetam(LEV) and Topiramate(TPM) on the MRP1 mRNA expression in the brain of chronic epileptic rats.Methods Epileptic rat models(n = 15) were made by stereotaxic injection of 1.5 μg(3 μl) kainic acid into the hippocampus of male SD rats,and the control rats(n = 15) given 3 μl normal saline(NS) in the same manner.Both the models and controls were randomized into subgroups of TPM,LEV and NS to receive oral TPM(50 mg/kg),LEV(40 mg/kg) and NS at an identical dose once daily for 30 days.Fluorescent quantitative RT-PCR was used to detect the expression of MRP1 mRNA in the temporal lobe and hippocampus of the rats.Results The expression of MRP1 mRNA in the hippocampus and temporal lobe of the epileptic rats was higher than that in the corresponding controls,but with no statistically significant difference.Nor were any significant differences observed in the level of MRP1 mRNA in hippocampus or temporal lobe among the TPM,LEV and NS subgroups either in the control or in the epilepsy group.Conclusion The expression of MRP1 mRNA is not obviously up-regulated in the brain of the rats with 1-month chronic epilepsy.TPM and LEV do not significantly change the level of MRP1 mRNA in the brain of either normal or epileptic rats.