Expression Of Mi R-92a And Angpt2 In Myocardial Ischemia Rats And Intervention Of Nicorandil

ObjectiveIn this study,we established a rat model of myocardial infarction to observe the effect of Nicorandil on ischemic myocardium and its relationship with the expression of miR-92 a and Angpt2Method90 adult male SD rats were randomly divided into sham operation group（sham group）,myocardial ischemia group（MI group）and myocardial ischemia + Nicorandil treatment group（MI + NCR group）,with 30 rats in each group.In sham group,the left anterior descending coronary artery（LAD）was not ligated;In MI group,only lad was ligated to make myocardial ischemia model;The MI + NCR group was given nicorandil by gavage after modeling,and the myocardial tissue was taken after immediate,4 weeks and 8 weeks respectively.He staining was used to observe the pathomorphological changes of myocardium in each group at different time periods;Real time fluorescence quantitative PCR（RT-PCR）was used to detect the expression levels of miR-92 a and Angpt2 in rat myocardium at different time periods;The measurement data were expressed by mean ± standard deviation（ ± ）.T-test and one-way ANOVA were used to compare whether the changes of the above indexes between and within each group were statistically significant（P < 0.05）.result1.HE stainingIn sham group,myocardial cells were evenly stained,neatly arranged and clearly striated;Compared with sham group,the injury of cardiomyocytes in MI group increased immediately,4 and 8 weeks after modeling,and the volume of cardiomyocytes increased,the nucleus staining was uneven,the arrangement was disordered,the transverse striation fracture disappeared,and the inflammatory cells infiltrated;The changes of myocardial tissue immediately after MI + NCR were the same as those in MI group.Myocardial tissue injury recovered in varying degrees at the4 th and 8th weeks.2.Gene expressionIntra-group comparison: The expression level of miR-92 a m RNA in the heart tissues of Sham group immediately after successful modeling had no difference with that of the samples taken at 4 and 8 weeks（P > 0.05）;The m RNA expression of miR-92 a and Angpt2 in group mi at the 4th week of sampling is higher than that in immediate group,and the m RNA expression of miR-92 a and Angpt2 at the 8th week is lower than that at the 4th week,with a statistically significant difference（p < 0.05）;the mrna expression of miR-92 a and Angpt2 in group MI+NCR at the 8th week is lower than that at the 4th week of sampling,with a statistically significant difference（p <0.05）.Inter-group comparison: There was no significant difference in pairwise comparison among the three groups of immediate materials（P > 0.05）;At the 4th and8 th week,compared with Sham group,the m RNA expression of miR-92 a and Angpt2 in myocardial tissue of MI group increased with statistical significance（P < 0.05）.Compared with MI group,the m RNA expression of miR-92 a and Angpt2 in MI+NCR group decreased with statistical significance（p < 0.05）conclusionThe expression of miR-92 a and Angpt2 is related to myocardial infarction in rats.The potential mechanism of nicorandil intervention in improving the injured myocardial tissue may be related to the inhibition of the expression of miR-92 a and Angpt2.