大鼠心脏非心肌细胞对心肌细胞收缩功能的影响及其与血管紧张素的关系

目的研究大鼠心脏非心肌细胞对心肌细胞α-肌球蛋白重链(α-MHC)及β-肌球蛋白重链(β-MHC)mRNA表达的影响及与血管紧张素受体的关系。方法分离、纯化、培养出生1~3 d的SD乳鼠心肌细胞(MC),同时制备非心肌细胞条件培养液(NMCM)。培养细胞的分组及药物干预:M组:MC+新鲜培养液;C组:MC+70%新鲜培养液+30%NMCM;L组:MC+新鲜培养液+AT1受体阻断剂〔氯沙坦(Losartan,10-6mol/L);〕CL组:MC+70%新鲜培养液+30%NMCM+Losartan;P组:MC+新鲜培养液+AT2受体阻断剂(PD123319,10-6mol/L);CP组:MC+70%新鲜培养液+30%NMCM+PD123319;LP组:MC+新鲜培养液+Losartan+PD123319;CLP组:MC+70%新鲜培养液+30%NMCM+Losartan+PD123319)。药物干预后24 h检测心肌细胞α-MHC及β-MHC mRNA的表达情况。结果C组、CP组的α-MHC表达明显低于其他组,差异有统计学意义(P<0.001),其余各组间差异无统计学意义。-βMHC mRNA表达的变化与此相反。结论非心肌细胞培养液可使心肌细胞MHC mRNA的表达从α亚型向β亚型转移。这种作用可能是非心肌细胞产生的AngⅡ通过AT1受体实现的。

The Impact of Nonmyocytes on the Expression of α-and β-Myosin Heavy Chain mRNA of Myocytes

Objective To study the impact of nonmyocytes conditioned media(NMCM) on the expression of α-and β-myosin heavy chain(MHC) mRNA of myocytes.Methods One to three-day-old SD rats were used.Cells were separated to myocytes and nonmyocytes(NMC) and the suspension of NMC was used as nonmyocyte conditioned media(NMCM).After 96 hours' culture,the myocytes were divided into 8 groups: group M: MC+new media;group C: MC+70% new media+30% NMCM;group L: MC+new media +Losartan(10^-6mol/L);group CL: MC+70% new media +30% NMCM+Losartan;group P: MC+ new media+ PD123319(10^-6mol/L);group CP: MC+ 70% new media +30% NMCM +PD123319;group LP: MC+new media+Losartan+PD123319;group CLP: MC+ 70% new media+30%NMCM+ Losartan+ PD123319.After 24 hours treatment,The expression of α-and β-myosin heavy chain(MHC) mRNA of myocytes were measured.Results The expression of α-MHC were lower in group C and CP than that in other groups.Losartan can inhibit the changing from α-to β-myosin heavy chain(MHC) mRNA.Conclusion NMCM can cause α-MHC changing to β-MHC.The changes could be inhibited by Losartan.