Role of reactive oxygen species in acetylcholine-induced preconditioning in cardiomyocytes.
Role of reactive oxygen species in acetylcholine-induced preconditioning in cardiomyocytes.
复制标题
活性氧在乙酰胆碱诱导的心肌细胞预处理中的作用。
DOI：
10.1152/ajpheart.1999.277.6.h2504
复制
发表时间：
1999
期刊：
影响因子：
--
通讯作者：
Schumacker,PT
中科院分区：
文献类型：
--
作者：
Yao,Z;Tong,J;Tan,X;Li,C;Shao,Z;Kim,WC;vandenHoek,TL;Becker,LB;Head,CA;Schumacker,PT
我们研究了ACh模拟心肌细胞缺血预适应的能力，以及ATP敏感性钾通道(KATP)和线粒体活性氧(ROS)在这一作用中的作用。在流通室中，控制流速、pH、PO2和PCO2条件下，对鸡胚心肌细胞进行了研究。细胞活力用碘化丙啶(5μM)定量，ROS产生用2‘，7’-二氯荧光素二乙酸酯测定。数据以均值±标准差表示。缺血10min，复氧10min或ACh(1 MM)10min，然后在缺血1h和复氧3h前停药，细胞死亡程度相同[预适应19±2%(n=6，P<；0.05)，ACh 21±5%(n=6，P<；0.05)vs对照组42±5%(n=9)]。与预适应一样，ACh使缺血前ROS生成增加3倍[0.60±0.16(n=7，P<；0.05)vs对照组，0.16±0.03(n=6)；任意单位]。选择性线粒体KATP通道拮抗剂5-羟基癸酸(5-HD，100μM)和抗氧化剂硫醇还原剂2-巯基丙酰甘氨酸(2-MPG，1 mM)[细胞死亡：5-HD+ACh 37±7%(n=5)，2-MPG+ACh 47±6%(n=6)；ROS信号：5-HD+ACh 0.09±0.03(n=5)，2-MPG+ACh 0.01±0.04(n=4)]可阻断ACh预适应的保护和ROS产生。此外，线粒体第三位电子传递抑制剂myxthiiazol(0.02±0.07，n=5)可阻断ACh诱导的ROS信号转导。这些结果表明，线粒体KATP通道的激活和线粒体产生的ROS增加是ACh诱导的心肌细胞预适应的重要细胞内信号。
We examined the ability of ACh to mimic ischemic preconditioning in cardiomyocytes and the role of ATP-sensitive potassium (KATP) channels and mitochondrial reactive oxygen species (ROS) in mediating this effect. Chick embryonic ventricular myocytes were studied in a flow-through chamber while flow rate, pH, P O 2 , and P CO 2 were controlled. Cell viability was quantified with propidium iodide (5 μM), and production of ROS was measured using 2′,7′-dichlorofluorescin diacetate. Data were expressed as means ± SE. Preconditioning with 10 min of ischemia followed by 10 min of reoxygenation or 10 min of ACh (1 mM) followed by a drug-free period before 1 h of ischemia and 3 h of reoxygenation reduced cell death to the same extent [preconditioning 19 ± 2% (n= 6,P< 0.05) ACh 21 ± 5% (n= 6,P< 0.05) vs controls 42 ± 5% (n= 9)]. Like preconditioning, ACh increased ROS production threefold before ischemia [0.60 ± 0.16 (n= 7,P< 0.05) vs. controls, 0.16 ± 0.03 (n= 6); arbitrary units]. Protection and increased ROS production during ACh preconditioning were abolished with 5-hydroxydecanoate (5-HD, 100 μM), a selective mitochondrial KATPchannel antagonist, and the thiol reductant 2-mercaptopropionyl glycine (2-MPG, 1 mM), an antioxidant [cell death: 5-HD+ACh 37 ± 7% (n= 5), 2-MPG+ACh 47 ± 6% (n= 6); ROS signals: 5-HD+ACh 0.09 ± 0.03 (n= 5), 2-MPG+ACh 0.01 ± 0.04 (n= 4)]. In addition, ACh-induced ROS signaling was blocked by the mitochondrial site III electron transport inhibitor myxothiazol (0.02 ± 0.07,n= 5). These results demonstrate that activation of mitochondrial KATPchannels and increased ROS production from mitochondria are important intracellular signals that participate in ACh-induced preconditioning in cardiomyocytes.