The Changes Of Gene Expression Of Potassium Channels Kv9.X And Effects Of Different Medicines On Their Changes In Post-MI Rat Heart

Part IThe changes and its signification of gene expression of potassium channels Kv9.X in post-MI rat heartObjective To study the changes and signification of the expression of potassium channels Kv9.X( Kv9.1, Kv9.2, Kv9.3) mRNA in post-MI rat heart. Methods Using a rat model of MI, induced by the left anterior descending coronary artery (LAD) ligation in female Sprague-Dawley rats, the living rats divided into post-MI group( 7 days group[n=10]; 30 days group[n=11]). Accordingly, the sham-operation group (sham-group) was established. Using semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), we measured Kv9.1, Kv9.2,Kv9.3mRNA in each group.Results 7 days group: Compared to the sham-group, Kv9.1, Kv9.2, Kv9.3mRNA inthe post-MI group remarkably decreases (P<0.05); 30 days group: compared to thesham-group, Kv9.1, Kv9.2, Kv9.3 mRNA in the post-MI group prominently reduces(P<0.01); post-MI group: compared to the 7 days group, Kv9.1, Kv9.2, Kv9.3 mRNA inthe 30 days group remarkably reduces (P<0.05).Conclusion The expression of potassium channels Kv9.1, Kv9.2, Kv9.3 mRNA aftermyocardial infarction exhibits the time-dependent downregulation. Part IIEffects of valsartan on the changes of expression of potassium channels Kv9.X in post-myocardial infarction ratObjective: To study the effects of valsartan on the changes of the expression of potassium channels Kv9.X (Kv9.1, Kv9.2, Kv9.3) of left ventricular non-infarcted myocardiums in post-myocardial infarction (post-MI) rats.Methods: Using a rat model of MI, induced by the left anterior descending coronary artery (LAD) ligation in female Sprague-Dawley rats, the living rats randomly divided into post-MI group ( 7 days group[n=10]; 30 days group[n=11]) or valsartan group(7 days group[n=10]; 30 days group[n=10]; valsartan 30mg.kg^-1.day^-1). Accordingly, the sham-operation group (sham-group) was established. Using semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), we measured Kv9.1, Kv9.2, Kv9.3 mRNA in each group.Results: Compared to MI groups, potassium channels Kv9.1, KV9.2, Kv9.3 mRNA in the valsartan groups remarkably increases regardless of on 7 days or 30 days (respectively, P<0.05; P<0.01). There is no difference between the valsartan groups and the sham-groups. Compared to the sham-groups, potassium channels Kv9.1, Kv9.2, Kv9.3 mRNA in the MI groups remarkably decreases regardless of on 7 days or 30 days (respectively, P<0.05; P<0.01). Compared to on 7 days after myocardial infarction,potassium channels Kv9.1, Kv9.2, Kv9.3 mRNA remarkably decreases on 30 days(P<0.05).Conclusion: Valsartan may reverse the downregulation of expression of potassiumchannels Kv9.1,Kv9.2,Kv9.3 mRNA in post-myocardial infarction rat markedly, whichis quick and absolute. Part IIIEffects of metoprolol on the changes of expression of potassium channels Kv9.X in post-myocardial infarction ratObjective: To study the effects of metoprolol on the changes of the expression of potassium channels Kv9.X (Kv9.1, Kv9.2, Kv9.3) of left ventricular non-infarcted myocardiums in post-myocardial infarction (post-MI) rats.Methods: Using a rat model of MI, induced by the left anterior descending coronary artery (LAD) ligation in female Sprague-Dawley rats, the living rats randomly divided into post-MI group (7 days group[n=10]; 30 days group[n=11]) or metoprolol group(7 days group[n=10]; 30 days group[n=9]; 8mg.kg^-1.day^-1). Accordingly, the sham-operation group (sham-group) was established. Using semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), we measured Kv9.1, Kv9.2, Kv9.3 mRNA in each group.Results: Compared to MI groups, potassium channels Kv9.1, Kv9.2, Kv9.3 mRNA in the metoprolol group remarkably increases on 30 days (P<0.05). Compared to the sham-groups, potassium channels Kv9.1, Kv9.2,Kv9.3 mRNA in the metoprolol groups remarkably decreases regardless of on 7 days or 30 days (P<0.05). Compared to the sham-groups, potassium channels Kv9.1, Kv9.2, Kv9.3 mRNA in the MI groups remarkably decreases regardless of on 7 days or 30 days (respectively, P<0.05; P<0.01).Compared to on 7 days after myocardial infarction, potassium channels Kv9.1 , Kv9.2,Kv9.3 mRNA remarkably decreases on 30 days (P<0.05).Conclusion: Metoprolol may reverse the downregulation of expression of potassiumchannels Kv9.1 , Kv9.2, Kv9.3mRNA in post-myocardial infarction rats and this reverseeffect is tardo.