基于不同钙释放机理的花萼海绵诱癌素A与去乙酰毛花苷的正性肌力作用研究  

Comparative Studies of Calyculin A and Deslanoside on Rat Isolated Heart Inotropy and Their Underlying Mechanism

作　　者：谢铭 黄惠丽 张文慧 高丽 陈龙 XIE Ming;HUANG Huili;ZHANG Wen hui;GAO Li;CHEN Long(National Standard Laboratory of Pharmacology for Chinese Materia Medica,Nanjing University of Chinese Medicine,Nanjing,210023,China;Institute of Chinese Medicine of Taizhou China Medical City,Taizhou,225300,China)

机构地区：[1]南京中医药大学国家科技部规范化中药药理实验室,江苏南京210023 [2]泰州中国医药城中医药研究院,江苏泰州225300

出　　处：《南京中医药大学学报》2018年第6期607-610,共4页Journal of Nanjing University of Traditional Chinese Medicine

基　　金：泰州中国医药城第四批"113人才计划"(2016024);江苏省自然科学基金(BK20151355)

摘　　要：目的与洋地黄类正性肌力代表药去乙酰毛花苷比较,研究蛋白磷酸酶(PP)抑制剂花萼海绵诱癌素A(Calyculin A)对心脏收缩力作用特点,分析Calyculin A正性肌力作用的钙释放机理。探讨能否以PP为靶点,开发正性肌力药物治疗心力衰竭。方法分别用Calyculin A(1,4,10nmol/L)和去乙酰毛花苷(0.1,1,10μmol/L)对大鼠离体心脏灌流,分析大鼠心率(HR)、左心室舒张压(LVDP)和最大上升速率(+dp/dtmax)的变化。采用Calyculin A(100nmol/L)和去乙酰毛花苷(10μmol/L)对大鼠左心室心肌细胞进行灌流,测定钙释放幅值、舒张期胞浆钙浓度(Ibaseline)及胞浆钙浓度恢复到静息状态值50%水平的时间(CTD50);分析Calyculin A(100nmol/L)和去乙酰毛花苷(10μmol/L)对咖啡因(20mmol/L)诱导的大鼠心肌细胞钙释放的影响,分析肌浆网钙泵活性(SERCA2a)、钠-钙交换体(NCX)及肌膜钙泵(PMCA)综合活性的变化。结果 Calyculin A(1,4,10nmol/L)与去乙酰毛花苷(0.1,1,10μmol/L)均能显著增加离体大鼠LVDP和+dp/dtmax(P<0.05),且减慢HR(P<0.05),并呈现浓度依赖性。Calyculin A(100nmol/L)与去乙酰毛花苷(10μmol/L)均显著增加钙释放幅值(P<0.05);Calyculin A还能显著降低Ibaseline(P<0.05),显著缩短CTD50(P<0.05)。Calyculin A(100nmol/L)显著增加肌浆网SERCA2a的速率常数(P<0.05);去乙酰毛花苷(10μmol/L)增加(NCX+PMCA)的速率常数(P<0.05),导致肌浆网SERCA2a在胞浆回吸收中所发挥作用的百分比下降(P<0.05)。结论 Calyculin A与去乙酰毛花苷对大鼠离体心脏作用没有显著区别,但Calyculin A通过增强肌浆网SERCA2a的活性,增加钙释放幅值并降低Ibaseline实现其正性肌力作用。Calyculin A的作用靶点PP,可作为一个潜在靶点用于开发正性肌力药物。OBJECTIVE To investigate the inotropic effect and its underlying mechanism of calyculin A,a protein phosphatase(PP)inhibitor,compared to deslanoside,a digitalis positive inotropic agent.To provide inputs whether PP can be served as a potential therapeutic target to develop pharmacological inotropic agents in treatment of heart failure.METHODS Ex vivo study was used to record the effects of calyculin A and deslanoside on rat isolated contractilities.They were perfused to follow in order:normal perfusion solution→calyculin A(1,4,10 nmol/L)or normal perfusion solution→deslanoside(0.1,1,10μmol/L).Ca 2+transients triggered by field stimulation and by caffeine(20 mmol/L)were measured to analyze the Ca 2+handling effects of calyculin A(100 nmol/L)and deslanoside(10μmol/L).RESULTS Both calyculin A(1,4,10 nmol/L)and deslanoside(0.1,1,10μmol/L)significantly increased the left ventricular developed pressure and the peak rate of rise of left pressure(P<0.05)and decreased the heart rate(P<0.05).Calyculin A(100 nmol/L)and deslanoside(10μmol/L)significantly increased the amplitude of Ca 2+transient and shortened the Ca 2+transient duration at 50%full recovery level(P<0.05);Calyculin A also lowered diastolic cytoplasm Ca 2+concentration(P<0.05).Calyculin A(100 nmol/L)significantly increased the SERCA2a activity and combinational activities of Na+Ca 2+exchanger(NCX)and plasma membrane Ca 2+ATPase(PMCA)(P<0.05);Deslanoside(10μmol/L)only increased combinational activities of NCX and PMCA(P<0.05),resulting in lowering percentage of contribution of SERCA2a in Ca 2+reuptake phase of Ca 2+transient(P<0.05).CONCLUSION Calyculin A increases the amplitude of Ca 2+transient by enhancing activity of SERCA2a and combinational activities of NCX and PMCA,resulting in the positive inotropy and favorable relaxation.PP can be a potential therapeutic target to develop pharmacological inotropic agents in treatment of heart failure.

关 键 词：花萼海绵诱癌素 去乙酰毛花苷 离体心脏 钙释放 

分 类 号：R285.5[医药卫生—中药学]