基于钙超载研究滇乌碱诱导大鼠心律失常的毒性机制

张祉思 程婉秋 江涛 沈志滨 陈艳芬 陈聪 司徒莹 唐春萍

中圖分类号 R285 文献标志码 A 文章编号 1001-0408（2021）23-2854-05

DOI 10.6039/j.issn.1001-0408.2021.23.07

摘 要 目的：研究滇乌碱诱导大鼠心律失常的毒性机制。方法：将32只大鼠按随机数字表法随机分为正常对照组，滇乌碱低、高剂量组（0.09、0.14 mg/kg）和乌头碱组（阳性对照，0.88 mg/kg），每组8只。各给药组大鼠每天灌胃相应药物1次，正常对照组大鼠灌胃等体积生理盐水，连续7 d。末次灌胃后，观察各组大鼠的心电图变化，测定大鼠心肌组织中腺苷三磷酸（ATP）含量、心肌细胞中Ca2+含量、心肌组织中Na+-K+-ATP酶和Ca2+-Mg2+-ATP酶活性以及雷诺定受体2（RyR2）、Ca2+-ATP酶（SERCA2）蛋白表达水平。结果：与正常对照组比较，滇乌碱低剂量组大鼠QRS波时限、校正后QT期间（QTc间期）均显著延长（P<0.01），心肌细胞中Ca2+含量显著升高（P<0.05），心肌组织中ATP含量、Ca2+-Mg2+-ATP酶活性、Na+-K+-ATP酶活性和SERCA2蛋白表达水平均显著降低（P<0.05或P<0.01）;滇乌碱高剂量组和乌头碱组大鼠心率均显著增快（P<0.05或P<0.01），QRS波时限、QTc间期均显著延长（P<0.01），心肌细胞中Ca2+含量均显著升高（P<0.01），心肌组织中ATP含量、Ca2+-Mg2+-ATP酶活性、Na+-K+-ATP酶活性和RyR2、SERCA2蛋白表达水平均显著降低（P<0.01）。结论：滇乌碱可导致大鼠心律失常;其作用机制可能与降低心肌组织中Ca2+-Mg2+-ATP酶、Na+-K+-ATP酶活性，下调心肌组织中钙转运相关蛋白RyR2、SERCA2的表达，从而导致Ca2+超载有关。

关键词 滇乌碱;心律失常;钙超载;腺苷三磷酸;雷诺定受体2;Ca2+-ATP酶;毒性机制

Study on the Toxicity Mechanism of Yunaconitine-induced Arrhythmia in Rats Based on Calcium Overload

ZHANG Zhisi1，CHENG Wanqiu1，JIANG Tao2，SHEN Zhibin1，CHEN Yanfen1，CHEN Cong1，SITU Ying1，TANG Chunping1，3（1.School of Traditional Chinese Medicine， Guangdong Pharmaceutical University， Guangzhou 510006， China; 2. Laboratory Animal Center， Guangdong Pharmaceutical University， Guangzhou 510006， China; 3. Guangdong Engineering Research Center for Local Precise Drug Delivery， Guangzhou 510006， China）

ABSTRACT   OBJECTIVE： To study the toxicity mechanism of yunacotine-induced arrhythmia in rats. METHODS： Totally 32 rats were randomly divided by random number table method into normal control group， yunacotine low-dose and high-dose groups （0.09， 0.14 mg/kg）， aconitine group （positive control， 0.88 mg/kg）， with 8 rats in each group. Administration groups were given the corresponding drugs once a day， and normal control group was given the constant volume of normal saline， for consecutive 7 d. After last intragastric administration， the changes of electrocardiogram （ECG） were observed. The contents of adenosine triphosphate （ATP） in myocardial tissue and Ca2+ in myocardial cells， the activities of Na+-K+-ATPase and Ca2+-Mg2+-ATPase as well as the protein expression of ranolidine receptor 2 （RyR2） and Ca2+-ATPase （SERCA2） in myocardial tissue were determined. RESULTS： Compared with normal control group， time limit of QRS wave and QTc intervals of rats were prolonged significantly in yunaconitine low-dose group （P<0.01）. The content of Ca2+ in myocardial cells， the ATP contents， the activities of Ca2+-Mg2+-ATPase and Na+-K+-ATPase as well as the protein expression of SERCA2 in myocardial tissue were reduced significantly （P<0.05 or P<0.01）. The heart rate of rats in yunaconitine high-dose group and aconitine group were increased significantly （P<0.05 or P<0.01）， and time limit of QRS wave and QTc intervals were significantly prolonged （P<0.01）; the content of Ca2+ in myocardial cells was increased significantly （P<0.01）; ATP content， the activities of Ca2+-Mg2+-ATPase and Na+-K+-ATPase， and protein expression of RyR2 and SERCA2 in myocardial tissue were decreased significantly （P<0.01）. CONCLUSIONS： Yunaconitine can induce arrhythmia in rats， the mechanism of which may be associated with Ca2+ overload that resulted from reducing the activities of Na+-K+-ATPase and Ca2+-Mg2+-ATPase and down-regulating the expression of related calcium transporter RyR2 and SERCA2.

KEYWORDS   Yunaconitine; Arrhythmia; Calcium overload; Adenosine triphosphate; Ryanodine receptor 2; Ca2+ ATPase; Toxicity mechanism

黄草乌Aconitum vilmorinianum Kom.为毛莨科乌头属多年生草本植物的干燥块根[1]，具有祛风散寒、活血止痛的功效，临床用于治疗风寒湿痹、跌打损伤和风湿关节疼痛等[2]，被收载于2005年版《云南省中药材标准》[3]。本课题组前期研究发现，黄草乌及其炮制品都有明显的镇痛作用，但其毒性剂量和疗效剂量接近，限制了其在临床的广泛使用[4]。……