尾加压素II介导心肌细胞肥大与其和钙离子的关系

UrotensinⅡ induced hypertrophy in cultured cardiac myocytes and the relation with calcium

目的 :观察尾加压素Ⅱ (UⅡ )对心肌细胞肥大的影响及其与钙离子的关系 ,为防治高血压左室肥厚提供理论依据。方法 :以培养的SD乳鼠心肌细胞为实验模型 ,通过测定心肌细胞表面积、蛋白含量和蛋白合成速率作为心肌细胞肥大的指标 ,应用激光共聚焦显微镜检测UⅡ作用后细胞内游离钙的变化。结果 :①随着UⅡ浓度的增加 ,心肌细胞表面积呈剂量依赖性增加 ,其中 10 -8和 10 -7mol/LUⅡ组心肌细胞表面积分别为 2 0 4 6± 2 6 8和 36 6 2± 2 5 9μm2 ,均明显高于对照组的 (936± 10 0 μm2 ) ,差异非常显著 (P <0 .0 1)。②随着UⅡ浓度的增加 ,心肌细胞的蛋白含量和蛋白合成速率呈递增趋势 ,其中 10 -8和 10 -7mol/LUⅡ组心肌细胞蛋白含量分别为 1.6± 0 .4和 1.9± 0 .3ng/cell,明显高于对照组 (0 .8± 0 .2ng/cell) ,差异非常显著 (P <0 .0 1)。蛋白合成速率分别为 2 5 0 8± 2 99和 2 898± 6 2 5cpm/well,与对照组的 (10 2 6± 92cpm/well)比较 ,差异非常显著 (P <0 .0 1)。③加入 10 -7mol/LUⅡ后心肌细胞内钙离子荧光强度迅速升高 (99.0± 14 .1) ,与对照组 (34.6± 5 .8)相比差异非常显著 (P <0 .0 1)。钙离子浓度由对照组的 (2 88± 15 9)上升至 (95 8± 6 6 4 ) ,二者之间差异亦非常显著 (P <0 .0 1)?

AIM:To observe the hypertrophy effect induced by urot en sinⅡ(UⅡ) on cultured cardiomyocytes and the relation with calcium.MET HODS:The effect of UⅡon cardiac myocyte (MC) hypertrophy was assessed by measurement of cell surface area, protein content and 3H-leucine incorpo ration, the UⅡ-induced changes of Ca 2+ in the MC were observed by means of laser scanning confocal microscope(LSCM). RESULTS: ①UⅡ inc reased MC surface area in a dose dependent manner. After 10 -8and 10 - 7 mol/L UⅡwere added,the cell surface areas were 2046±268 and 3662±259 μm 2, respectively,significantly higher than the surface area of the control( P<0.01).②10 -8 and 10 -7 mol/L UⅡincreased 3H-leucine incorporation also in a dose dependent manner. The protein content were 1.7±0 .4 and 1.9±0.3(ng/cell)respectively, and 3H-leucine incorporations wer e 2508±299 and 2898±625 (cpm/ well) respectively.They were all significantly higher than those of the control(P<0.01).③A rapid increase of Ca 2+ in MC was observed shortly after 10 -7 mol/L UⅡ was added in cultured M C.CONCLUSION: UⅡcan induce cardiac myocyte hypertrophy and incre ase of calcium,and calcium maybe was the key factor in the hypertrophy effect induced by UⅡ,which could be useful for the prevention of left ventricular hype rtrophy.