乌头碱、新乌头碱及次乌头碱对心肌细胞钙释放的影响

Effects of aconitine, mesaconitine and hypaconitine on calcium release in isolated adult rat cardiac myocytes

目的：探讨乌头碱、新乌头碱、次乌头碱对心肌细胞钙释放的影响。方法分离的成年Sprague-Dawley大鼠左心室心肌细胞分别使用0.3、1、3μmol/L乌头碱、新乌头碱、次乌头碱溶液灌流12 min，灌流后4、8、12 min时检测自发性钙释放（SCR）诱发率以及舒张末期钙浓度（F0）、钙瞬变幅度（ΔF）的变化。检测灌流0.3μmol/L乌头碱、新乌头碱、次乌头碱溶液后12 min，心肌细胞发挥正性肌力作用时钙瞬变和收缩功能动力学指标的变化。结果乌头碱、新乌头碱、次乌头碱均可诱发SCR，0.3μmol/L时新乌头碱SCR诱发率最高，3μmol/L时乌头碱SCR诱发率最高。与对照组比较，给药后12 min，3μmol/L乌头碱、新乌头碱、次乌头碱均可增加 F0[（1.459±0.379）、（1.585±0.493）、（1.213±0.254）比（1.079±0.108）]、ΔF[（1.615±0.455）、（2.210±0.756）、（1.528±0.422）比（1.036±0.125）]，差异有统计学意义（P均＜0.05）；且新乌头碱ΔF高于乌头碱和次乌头碱（P均＜0.05）。与对照组比较，0.3μmol/L乌头碱、新乌头碱、次乌头碱均可增加ΔF[（0.409±0.127）、（0.423±0.107）、（0.414±0.118）比（0.260±0.065）；P＜0.05或P＜0.01]、收缩幅度[（5.464±2.239）%、（7.449±2.548）%、（5.524±1.645）%比（3.428±0.911）%；P＜0.05或 P＜0.01]，延长钙瞬变达峰时间[（0.041±0.016）s、（0.039±0.009）s、（0.038±0.011）s 比（0.032±0.007）s；P＜0.05或P＜0.01]；与乌头碱组比较，新乌头碱和次乌头碱可降低钙瞬变消除时间常数[（0.301±0.054）s、（0.324±0.064）s 比（0.361±0.076）s；P＜0.05或P＜0.01]，缩短舒张期收缩恢复至50%时的时间[（0.124±0.035）s、（0.126±0.040）s 比（0.157±0.056）s；P＜0.05或 P＜0.01]。结论乌头碱、新乌头碱、次乌头碱的正性肌力作用与毒性效应同时存在，表明心肌细胞内钙浓度升高是产生正性肌力作用的有利因素，也是诱发SCR的危险因素。

ObjectiveTo investigate the effects of aconitine, mesaconitine and hypaconitine on calcium release in isolated adult rat cardiac myocytes.MethodsThe left ventricular cardiac myocytes isolated from adult Sprague-Dawley rats were perfused withacnitine, mesaconitine and hypaconitine at 0.3 μmol/L, 1μmol/L, 3 μmol/L for 12 min. The spontaneous calcium release （SCR） rate, the end-diastolic[Ca2＋]（F0） and the calcium transient amplitude （ΔF） were detected 4 min, 8 min and 12 min after the perfusion. 12 min after the perfusion with acnitine, mesaconitine and hypaconitine at 0.3 μmol/L, the changes of systolic dynamics and calcium transient were detected for the positive inotropic effect. Results Any of aconitine, mesaconitine and hypaconitine induced SCR, mesconitine-induced SCR rate was highest at low concentration （0.3 μmol/L）, and＆amp;nbsp;aconitine-induced SCR rate highest at high concentration （3 μmol/L）. Compared with the control, 12 min after the perfusion with acnitine, mesaconitine and hypaconitine at 3 μmol/L elevated F0 （1.459 ± 0.379, 1.585 ± 0.493, 1.213 ± 0.254vs.1.079 ± 0.108, allP〈0.05） and ΔF（1.615 ± 0.455, 2.210 ± 0.756, 1.528 ± 0.422vs. 1.036 ± 0.125, allP〈0.05）, mesaconitine with ΔF higher than aconitine and hypaconitine. At low concentration （0.3 μmol/L）, compared with control, aconitine, mesaconitine and hypaconitine increased ΔF （0.409 ± 0.127, 0.423 ± 0.107, 0.414 ± 0.118vs.0.260 ± 0.065;P〈0.05 orP〈0.01） and contraction amplitudes （5.464% ± 2.239%, 7.449% ± 2.548%, 5.524% ± 1.645%vs.3.428% ± 0.911%;P〈0.05 orP〈0.01）, prolonged the time to peak of calcium transient （0.041 ± 0.016 s, 0.039 ± 0.009 s, 0.038 ± 0.011 svs.0.032 ± 0.007 s;P〈0.05 or P〈0.01）; compared with aconitine, mesaconitine and hypaconitine decreased calcium transient time constant （0.301 ± 0.054 s, 0.324 ± 0.064 svs.0.361 ± 0.076 s;P〈0.05 orP〈0.01） and diastolic t50 （0.124 ± 0.035 s, 0.126 ± 0.040 svs.0.157 ± 0.056 s;P〈0.05 orP〈0.01）.ConclusionsAconitine, mesaconitine and hypaconitine reveal the positive inotropic effects couple with the toxic effects. Increased[Ca2＋]in cardiac myocytes is the key factor for the positive inotropic effects, but also the risk factor for SCR.