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目的探讨人参皂苷Rg1(ginsenoside Rg1,Rg1)对血管紧张素Ⅱ(angiotensinⅡ,AngⅡ)所致心肌细胞肥大的影响,并初探其分子机制。方法在培养的新生大鼠心肌细胞中加入AngⅡ0.1μmol.L-1,HE染色观测细胞形态学变化,并以心肌细胞直径?蛋白含量和心房利钠因子(atrial natriuretic factor,ANF)mRNA的表达为肥大指标。为分析药物的作用机制,用Fura-2/AM负载心肌细胞检测细胞内游离钙浓度[Ca2+]i;并检测钙调神经磷酸酶(calcineurin,CaN)mRNA的表达变化。ANF和CaN mRNA的表达采用Real-time PCR测定。结果AngⅡ0.1μmol.L-1使心肌细胞直径明显增大,蛋白质含量明显增加,并使ANF mRNA的表达显著升高。加入Rg1 15.6、31.2和62.4μmol.L-1使AngⅡ所增大的心肌细胞直径分别缩短13%、33%、43%(P<0.01);并使心肌细胞蛋白含量分别减少10%、14%和19%(P<0.01),Rg1 62.4μmol.L-1还显著抑制AngⅡ所上调的ANF mRNA的表达。与此同时,上述浓度的Rg1还使AngⅡ所升高的[Ca2+]i分别抑制了19.3%?28%和38.6%(P<0.01,n=6);Rg1 62.4μmol.L-1还使AngⅡ所升高CaN mRNA的表达明显降低。结论Rg1可抑制AngⅡ诱导的心肌细胞肥大,该作用可能与其降低由AngⅡ所升高的心肌细胞[Ca2+]i,并由此而抑制Ca2+-CaN信号通路有关。
Objective To investigate the effect of ginsenoside Rg1 (Rg1) on cardiomyocyte hypertrophy induced by angiotensin Ⅱ (AngⅡ) and its molecular mechanism. Methods AngⅡ0.1μmol.L-1 was added to cultured neonatal rat cardiomyocytes. The morphological changes of the cells were observed by HE staining. The expression of cardiac cell diameter protein and atrial natriuretic factor (ANF) mRNA For hypertrophy indicators. To analyze the mechanism of action of drugs, the intracellular free calcium concentration [Ca2 +] i was detected by Fura-2 / AM loaded cardiomyocytes, and the expression of calcineurin (CaN) mRNA was detected. The expression of ANF and CaN mRNA was determined by Real-time PCR. Results AngⅡ0.1μmol.L-1 significantly increased the diameter of myocardial cells, the protein content was significantly increased, and the ANF mRNA expression was significantly increased. The diameter of myocardial cells increased by AngⅡwas shortened by 13%, 33%, 43% (P <0.01) by adding Rg1 15.6, 31.2 and 62.4μmol.L-1, respectively, and the protein content of cardiomyocytes was decreased by 10% and 14% And 19% (P <0.01). Rg1 62.4μmol.L-1 also significantly inhibited AngⅡ-up-regulated ANF mRNA expression. At the same time, Rg1 also inhibited [Ca2 +] i increased by AngⅡ by 19.3% -28% and 38.6%, respectively (P <0.01, n = 6); Rg1 62.4μmol.L- Increased expression of CaN mRNA was significantly reduced. Conclusion Rg1 can inhibit Ang Ⅱ-induced cardiomyocyte hypertrophy, which may be related to the decrease of [Ca2 +] i in myocardial cells induced by AngⅡ, and thus the inhibition of Ca2 + -CaN signaling pathway.