左旋氨氯地平对缺氧心肌细胞钙信号系统的影响

Effect of l-amlodipine on calcium signaling system in anoxic myocardial cells

目的:观察缺氧对心肌细胞内游离钙离子浓度和细胞膜及肌浆网上钙离子泵,即Ca2+ AT Pase表达的影响及左旋氨氯地平的干预作用。方法:制备大鼠心肌细胞缺氧模型,随机分为正常对照组、缺氧损伤组和左旋氨氯地平组。测定心肌细胞内游离钙离子的浓度(FURA2 /AM荧光探针法)、细胞膜上Ca2+ ATPase表达水平(RT PCR法)以及肌浆网上钙泵(SERCA2 )含量(WesternBlot法)。结果:缺氧损伤组心肌细胞内游离钙离子浓度[ (716±s164)nmol·L-1 ]较正常对照组[ (208±32)nmol·L-1 ]显著上升(P<0. 01 ),细胞膜及肌浆网上钙泵的表达(0. 54±0. 12和158±15)较正常对照组( 0. 86±0. 07和210±12 )均明显降低(均P<0. 01),经左旋氨氯地平干预后细胞内游离钙浓度降低至(359±75 )nmol·L-1,P<0. 01,细胞膜上及肌浆网上钙泵的表达(0. 81±0. 11和184±11)均明显增强(均P<0. 01)。结论:左旋氨氯地平可能通过增加细胞膜及肌浆网上钙泵的表达有效减轻心肌细胞内的钙超载,对缺氧心肌具有保护作用。

AIM: To study the effects of anoxia on the dissociative calcium concentration of myocardial cells and the expression of membranou Ca 2+-ATPase (both on the cell membrane and the sarcoplasmic reticulum), then the protective effect of l-amlodipine on anoxic myocardial cells. METHODS: Rat myocardial cells were cultured and divided into three groups randomly, the normal control group, anoxic injured group and l-amlodipine group. Then the anoxic model was set up, and followed by measurement of the dissociative calcium concentration (with FURA2/AM fluorescent probe), the expression of membranou Ca 2+-ATPase (by RT-PCR )and the content of endoplasmic reticulum Ca 2+-ATPase (SERCA2, using Western Blot), for each group. RESULTS: The dissociative calcium concentration of the anoxic injured group was significantly higher than that of the normal control group ((716±s 164) vs (208±32) nmol·L -1, P<0.01) while the expression of membranou Ca 2+-ATPase( 0.54± 0.12 vs 0.86 ±0.07) and the content of endoplasmic reticulum SERCA2(158±15 vs 210±12) in the anoxic myocardial cells were lower than those in the normal control group (P <0.01). The l-amlopdipine could decrease the dissociative calcium concentration((359± 75) vs (716±164) nmol ·L -1) and increase the expression of membranou Ca 2+-ATPase ( 0.81± 0.11 vs 0.54± 0.12)and the content of endoplasmic reticulum SERCA2 (184±11 vs 158±15, P< 0.01). CONCLUSION: Intracellular l-amlodipine could protect the anoxic myocardial cells by reducing the intracellular Ca 2+-overload and increasing the expression of membranou Ca 2+-ATPase and content of endoplasmic reticulum SERCA2.