牛磺酸在体外对缺血/再灌注新生大鼠心肌细胞内游离钙的影响

目的:观察低氧、复氧对心肌细胞内Ca2+浓度(Ca2+]i)的影响,以及牛磺酸模拟心肌缺血/再灌注(I/R)过程中减轻钙超载的作用。方法:采用SD大鼠乳鼠进行心肌细胞培养,建立模拟I/R模型。实验分4组:①正常对照组;②模拟缺血/缺氧组:细胞低氧180min;③模拟I/R组:细胞低氧180min,复氧180min;③牛磺酸+I/R组:先加入终浓度为20mmol.L-1的牛磺酸,再行低氧180min,复氧180min。以Fluo-4/AM荧光指示剂负载,应用激光共聚焦显微镜技术检测心肌细胞Ca2+]i变化。结果:对照组心肌细胞Ca2+]i荧光强度(23.71±2.37)U和荧光光密度较低;低氧180min后复氧即刻,Ca2+]i荧光强度开始增加(57.52±8.31),复氧180min后Ca2+]i荧光强度(71.13±4.74)U和光密度显著增高(P<0.01vs对照组)。而牛磺酸组细胞内荧光强度和光密度较模拟I/R组显著降低(42.42±4.17)U vs(71.13±4.74)U,P<0.01]。结论:心肌细胞缺血/缺氧导致Ca2+超载;模拟I/R Ca2+超载加剧,而牛磺酸有明显减轻心肌细胞模拟I/R时Ca2+超载的作用。

Effect of taurine on the concentration of free calcium in cultured myocardial cells of neonatal rat exposed to ischemia and reperfusion

To study the effects of taurine on intracellular calcium concentration in cultured myocardial cells of neonatal SD rat exposed to ischemia and reperfusion.Intracellular calcium was detected by Fluo-4/AM with confocal microscopy. Ischemia was induced by incubating the cells in nitrogen for 180min.Reperfusion was made by incubation the cell in anoxia condition for 180 min following ischemia treatment.20 mmol/L taurine was added to culture medium before ischemia and reperfusion treatment.After 180min exposed to hypoxia the intracellular calcium increased remarkably from normal level of 23.71+2.37U to 57.52+8.31U.The intracellular calcium increased significantly to 71.13+4.74U after ischemia-reperfusion treatment.The concentrate of intracellular calcium was inhibited significantly to 42.42+4.17U after taurine treatment.The results suggested that hypoxia and reperfusion treatment could induce the calcium overload in cultured myocardial cells and the taurine could inhibite that intracellular calcium overloading significantly.