Apelin对心肌细胞肥大的影响

Effects of exogenous Apelin on cardiomyocyte hypertrophy

目的近有研究表明在肥大心肌中,“孤儿受体”APJ的内源性配基-Apelin减少。由此推测Apelin的水平与心肌细胞肥大可能存在某种联系。本实验旨在观察外源性提高Apelin水平对血管紧张素Ⅱ(angiotensinⅡ,AngⅡ)诱导的心肌细胞肥大的影响,并探讨其可能的机制。方法体外培养Sprague-Daw ley乳鼠心肌细胞,进行分组实验。各组在加入干预因素后第5天终止实验。测量心肌细胞的直径、表面积及其蛋白质含量,并测定上清液中一氧化氮(NO)的含量。结果AngⅡ(0.1μmol/L)单独作用可引起心肌细胞直径、表面积及蛋白质含量的显著增加(P<0.01),但联合给予Apelin(1μmol/L)可以减弱AngⅡ诱导的细胞大小及蛋白质含量的增加(P<0.05)。AngⅡ0.1μmol/L单独作用时细胞培养液中NO含量显著减少(P<0.01),但联合给予Apelin(1μmol/L)后细胞培养液中NO含量显著增加(P<0.05)。相关性分析显示培养液中的NO含量分别与以上3种肥大指标呈负相关(r=-0.623,P<0.01;r=-0.731,P<0.01;r=-0.584,P<0.01)。结论Apelin能够抑制AngⅡ诱导的心肌细胞肥大,这一作用可能与NO生成增加有关。

AIM Recent studies show that in the hypertrophic myocardium, Apelin, the endogenous ligand for the orphan G-protein-coupled receptor APJ, decreases. We then hypothesize that there may exist some relation between Apelin level and cardiac hypertrophy. The purpose of the present study was to examine the effect of exogenous Apelin on angiotensin Ⅱ （ Ang Ⅱ ） -induced cardiomyocyte hypertrophy and explore the possible underlying mechanism. METHODS Neonatal cardiomyocytes of SD rats were cultured in vitro. Five days after pretreatment, the surface area, the diameter, the protein content of the myocyte and nitric oxide （NO） in the culture solution were measured. RESULTS Ang Ⅱ 0.1 μmol/L alone caused obvious increases in the diameter, surface area and protein content of myocyts（ P 〈0.01 ） , however, co-administration of Apelin（ 1 μmol/L） inhibited Ang Ⅱ-induced increases in cell size and protein content（P 〈0.05）. In addition, Ang Ⅱ 0.1 μmol/Lalone caused a decrease of NO content in the culture solution（P 〈0.01 ）,but co-administration of Apelin（ 1 μmol/L） led to increased amount of NO compared with Ang Ⅱ alone （ P 〈 0.05 ）. Correlation analysis showed the content of NO in the culture so- lution had a negative correlation with the above three hypertrophic indexes respectively （ r = - 0. 623, P 〈0.01; r= -0.731, P〈0.01; r= -0.584, P〈0.01）. CONCLUSION Apelin attenuates angiotensin Ⅱ-induced cardiomyocyte hypertrophy . Nitric oxide seems to play a role in this antihypertropic process.