Effect of Tenidap on expression of inwardly rectifying potassium channel 2.3 in hippocampi of chronic temporal lobe epileptic rats / 中华神经科杂志

ABSTRACT

Objective To observe the change of expression of inwardly rectifying K+(Kir)2.3 mRNA and protein of Kir in the hippocampus of rats with chronic temporal lobe epilepsy(TLE)in different time points and the effect of Tenidap a Kir2.3 channel opener on its expression,investigate the relationship between Kir2.3 and the pathogenesis of TLE and to explore the potential of Kir agonists as anti-epileptic drugs.Methods The pilocarpine TLE rat model was used.Animals were randomly assigned to the control or the status epilepticus(SE)groups,which were further divided into four time point subgroups consisting of 0.6,72 hours,and 2 weeks post-SE termination.Another subgroup was given Tenidap,a Kir2.3 channel opener,and tested 2 weeks post-SE.Hippoeampi were removed and the expression of Kir2.3 mRNA and protein at different time points was measured by reverse transcription polymerase chain reaction(RT-PCR)and western blotting.Results The ratios of Kir2.3 mRNA and β-actin in normal control and 0,6,72hours and 2 weeks after SE termination were 0.080±0.030,0.103±0.045,0.164±0.026,0.132±0.024.0.011±0.008,respectively(F=23.684,P<0.01).The ratios of Kir2.3 protein and GAPDH in propotional groups were0.305±0.030,0.263±0.028,0.767±0.167,0.498±0.077,0.176±0.026(F=44.183.P<0.05).The expression of Kir2.3 channel in the epileptic rats was bimodal,increasing immediately after SE,relative to controls,and declining in the chronically epileptic period.Tenidap administration upregulated both the mRNA(0.021±0.006)and protein expression(0.636±0.140) of Kir2.3(F=25.216 and 47.355,P<0.05 and 0.01).Condusion These findings suggest that the pathogenesis of TLE is accompanied by a decrease in Kit2.3 expression,which may be ameliorated by the administration of tenidap.