雌激素对大鼠心肌细胞钙的调控作用研究

The effects of estrogen on calcium mobilization in cardiac myocyte of rat

目的 观察雌激素对大鼠心肌细胞钙转运的调控作用。方法 应用膜片钳全细胞记录方法观察L型钙通道电流 (ICa .L) ,共聚焦显微镜系统分析细胞内钙浓度 ([Ca2 + ]i)的变化。结果 应用 10 μmol·L-1和 30 μmol·L-1的 17β Estradiol,分别使ICa .L 抑制到正常的 48 1%± 4 5 %and2 9 3%± 5 2 % (n =5 ,P <0 0 1)。 10 μmol·L-1的 17β Estradiol可升高静息的培养心肌细胞 [Ca2 + ]i,荧光强度 (FI)值由 5 4 2± 13 6增加到 86 5± 15 3(n =6 ,P <0 0 5 ) ;而对具有自发收缩的心肌细胞钙瞬变幅度有明显的抑制作用 ,由给药前的 18 5± 4 3减小到 11 4± 3 9(n =6 ,P <0 0 5 )。17β Estradiol可剂量依赖性地抑制ICa.L。结论 L型钙通道等多种机制参与雌激素对大鼠心肌细胞钙转运的调控作用。

AIM The effects of estrogen on the calcium mobilization in cardiomyocytes is not clear to date, the present study is designed to investigate the possible effects. METHODS L type calcium current was recorded using whole cell configuration of the patch clamp technique and intracellular calcium concentration was measured with confocal microscopy. RESULTS After using 10 μmol·L -1 and 30 μmol·L -1 17β estradiol, the peak inward calcium current was decreased to 48 1%±4 5% and 29 3%±5 2% of the control respectively( n =5, P <0 01). 17β estradiol(10 μmol·L -1 ) increased the calcium fluorescent intensity(FI) of quiescent cultured cardiomyocytes from 54 2±13 6 to 86 5±15 3 ( n =6, P <0 05), but decreased the calcium transient amplitude in spontaneously beating cardiomyocytes from 18 5±4 3 to 11 4±3 9( n=6, P <0 05). CONCLUSION Estrogen regulates calcium mobilization in cardiomyocytes of rats and different mechanism including L type calcium channel is involved in the effects of estrogen.