Expression Of Multidrug Resistance Associated Protein 1 MRNA In Chronic Epileptic Rats Brain.

【Objective】Mechanisms underlying refractory epilepsy (RE) are still not understood. Multidrug resistance associated protein 1 (MRP1) has been confirmed to correlate with resistance to anticancer drugs. Arouse of interest indicated that MRP1 may also be up-regulated in epileptic foci from patients with refractory epilepsy. It is not known whether overexpression of MRP1 is due to epilepsy itself, and seizures or long-term effect of antiepileptic drugs. The aim of this study is to investigate the influence of spontaneous seizures, levetiracetam (LEV) and topiramate (TPM) on MRP1 mRNA expression in chronic epileptic rats brain.【Methods】The epileptic rat models were made with 1.5μg (3μl) Kainic acid stereotaxic injected into male SD rats' hippocampus and the control group rats were injected with 3μl normal saline (NS). The rats in epilepsy group (15 rats) and control group (15 rats) were randomized into TPM, LEV and NS subgroups to receive once-daily orally feeding of TPM (50 mg/ kg) , LEV (40 mg/ kg) and NS (same amount NS) for 30 d. Fluorescent quantitative RT-PCR was used to detect the expression of MRP1 mRNA in the temporal lobe and hippocampus of rats.【Results】The expression of MRP1 mRNA in hippocampus and temporal lobe in epilepsy groups was higher than those in corresponding control groups, but there was no significant difference between them. Either in control groups or in epilepsy groups, no significant difference of the level of MRP1 mRNA was observed in hippocampus or temporal lobe among TPM, LEV or NS subgroups. 【Conclusions】No up-regulation of MRP1 mRNA expression is found in 1 month chronic epileptic rats brain. The level of MRP1 mRNA in normal or epileptic rats brain is not significantly changed by TPM or LEV treatment.