急性心肌梗死大鼠左心室心肌组织脑利钠肽表达变化

Brain natriuretic peptide expression after acute myocardial infarction in Sprague-Dawlay rats

目的研究Sprague-Dawlay大鼠急性心肌梗死(AMI)后左心室心肌组织脑利钠肽(BNP)表达的动态变化。方法结扎冠状动脉左前降支,建立大鼠AMI模型。随机分为AMI组(1、3、7、14、28d组)和假手术组,半定量RT-PCR和Western blot分别检测左心室心肌组织中BNP mRNA和蛋白的表达水平。结果与假手术组相比,左心室心肌组织BNP mRNA和蛋白表达于梗死后1d开始升高,BNP mRNA表达为0.913±0.036比0.757±0.034(P<0.05),BNP蛋白表达为0.882±0.027比0.565±0.086(P<0.05);3d达高峰,BNP mRNA和蛋白表达分别为0.971±0.027,0.976±0.016;然后逐渐降低,但至28d仍高于假手术组,BNP mRNA表达为0.902±0.072比0.757±0.034(P<0.05),BNP蛋白表达为0.873±0.033比0.565±0.086(P<0.05)。结论大鼠AMI后左心室心肌组织脑利钠肽表达增高,并且呈一定的动态变化规律。

Objective To investigate left ventricular expression of brain natriuretic peptide （BNP） in Sprague-Dawlay rats with acute myocardial infarction （AMI）. Methods Myocardial infarction model was established by anterior descending coronary artery ligation. Rats were randomized to AMI groups（ 1 day, 3 days, 7 day, 14 days, 28 days） and Sham-operated group. Semi-quantitative RT-PCR and Western blot were used to examine BNP mRNA and protein levels in left ventricular. Results Compared with the Sham-operated group, the mRNA and protein levels of BNP in AMI groups were significantly increased at 1 day, BNP mRNA levels were 0.913 ± 0.036 vs 0. 757 ± 0.034 （ P 〈 0.05）, BNP protein levels were 0. 882 ± 0. 027 vs 0. 565 ±0. 086 （ P 〈 0.05）, peaked at 3 days, BNP mRNA and protein levels were 0.971 ±0.027 and 0. 976 ±0. 016 respectively, then decreased, however, it remained higher than that in Sham-operated group even in 28 days, BNP protein levels were. 902 ± 0. 072 vs 0.757 ± 0.034 （ P 〈0. 05）, BNP protein levels were 0. 873 ± 0. 033 vs 0. 565 ±0. 086 （ P 〈 0.05）. Conclusion The ventricular expression of BNP is increased after AMI, and presents dynamic changes.