Expression Of Intermediate Conductance Ca～(2+)-activeted K～+ MRNA Channels In Intimal Proliferation In Rat Aorta And Intervention Study Of Losartan

Objectives To investigate the dynamic change of intermediate conductanceCa²⁺-activated k⁺ channels (IKCa1) mRNA and its effect on intimal proliferation afterballoon catheter injury(BCI). To evaluate the effect of hyperlipemia and losartan onthe expression of IKCa1 mRNA after BCI.Methods 72 rats were divided into 3 groups at random, 8 of them were incontrol group, 40 rats were in BCI group and the rest were in group that fed withsuperfatted diet. BCI group were divided into 5 subgroups, 1day,4day,7day,14day,28day. Superfatted diet group were divided into 3 subgroups, 2of them were fed with different dosage losartan respectively . IKCa1 mRNA level ontime course were investigated with semi-quantitative reverse transcriptionpolymerase chain reaction (RT-PCR). Location of IKCa1 channels was observed withimmunohistochemistry. We investigated the effect of hyperlipemia on expression ofIKCa1 mRNA. We also investigated the effect of losartan on expression of IKCa1mRNA after BCI complicated with hyperlipemiaResults Experssion of IKCa1 mRNA was upregulated and reached themaximum at the first day after BCI. IKCa1 channels could be located oncytomembrane, cytoplasm, nucleus of proliferative intima. Hyperlipemia was found.Experssion of IKCa1 mRNA was upregulated by hyperlipemia and reduced bylosartan after BCI complicated with hyperlipemia.Conclusions The upregulation of IKCa1 mRNA after BCI may be one offactors that promote intimal proliferation. The expression of IKCa1 mRNA may bemore obviously increased by hyperlipemia and reduced by losartan after BCI plushyperlipemia. IKCa1 channels could be located on cytomembrane, cytoplasm, nucleusof proliferative intima.