Reversal Of Multidrug Resistance Protein In Phenytoin Resistant Epilepsy Mouse Model By Flunarizine

Objective:Exploring multidrug resistance protein reversal effect and preliminarymechanisms of Flunarizine, Investigating the protective effect of the the drug in thebrain.Methods:1.Using the pentylenetetrazol40mg/kg, intraperitoneal injection, continuousadministration of7-day, and then continuous oral gavage for a total of14days ofphenytoin40mg/kg in mice, at last, filter out phenytoin-resistant epilepsy mouse model,inspecting level of mouse seizures and seizure frequency during the entire period.2.Drug-resistant epilepsy mice were randomly divided into phenytoin group(continuous production of drug-resistant epilepsy model), positive verapamil group(drug-resistant model, injection20mg/kg verapamil on the basis of the controlintraperitoneal injection), flunarizine group (based on the resistance model given byintraperitoneal injection of flunarizine dihydrochloride solution8mg/kg), and then theseizures conditions were observed in there groups of mouse.3. Mice were sacrificed after four days continuous administration of differentdrugs, westernblot methods were used to investigate P-glycoprotein expression in brain4. Each group of mice were short-necked putting to death after continuousadministration of different drugs for4days, and the brain were for HE staining andimmunohistochemistry to examine the abnormal structure of the mouse brain neuronand the expression of caspase-3.Results:1. After administion of pentylenetetrazol in mouse,all the mice were able toachieve "showing at least five consecutive stage2seizures or three consecutivve stage4seizures",and then all mice were given phenytoin for14days,80%of mice showed " at least five consecutive stage2seizures or three consecutivve stage4seizures", whichidentified for drug-resistant epilepsy modle.2. After four consecutive days of administration of differents drugs, The epilepsywas reduced in the positive control verapamil group comparing to the resistant epilepsymodel group (control)(P <0.05), flunarizine significantly reduced the epilepsy in micecomparing to resistant epilepsy model group (P <0.01), flunarizine and phenytoin incombination in4days can effectively reduced the mice attack level of0.83stage (meandifference0.83, mean difference95%confidence interval0.39-1.27).3. Westerblot method showed that given Flunarizine were significantly reducedthe expression of P-glycoprotein (P <0.01) in brain of phenytoin drug-resistant epilepsymouse model.Flunarizine was better than the positive control verapamil (P <0.05).4. Neuronal damage was observed in the hippocampus or cortex by histochemicalstudy of mice in each group. the neuronal damage was occured in verapamil andflunarizine group. Immunohistochemistry showed that compared with the control group,drug-resistant epilepsy group(control)showed a high degree of expression of Caspase-3.The caspase-3expression of flunarizine group was lower than control group.ConclusionsPhenytoin and flunarizine in combination could significantly reduce thephenytoin-resistant epilepsy, reduce P-glycoprotein expression in brain tissue, and haveprotective effect of brain tissue in drug-resistant epilepsy mouse model...