川芎嗪及其硝酮衍生物对HCN4通道和窦房结细胞起搏电流的抑制作用

发布时间：2018-06-22 11:38

本文选题：川芎嗪 + 川芎嗪硝酮衍生物　；参考：《武汉科技大学》2015年硕士论文

【摘要】：目的：探讨川芎嗪（Ligustrazine，TMP）及其硝酮衍生物（TBN）对超极化激活环核苷酸门控阳离子通道（hyperpolarization-activated cyclic nucleotide-gatedcation channel，HCN）基因家族亚型HCN4参与编码的超极化激活的阳离子通道电流（If）和家兔窦房结细胞动作电位的影响。方法：利用标准的双极电压钳和标准玻璃微电极技术记录表达在非洲爪蟾卵母细胞上的HCN4通道电流以及家兔窦房结动作电位。结果：正常表达在卵母细胞上的HCN4通道电流，给予1μM、10μM、100μM川芎嗪（TMP）后，以浓度依赖性方式阻断HCN4参与编码的If电流，其半数最大效应浓度[IC50]为48.79±3.1μmol/L，希尔系数为1.01±0.3。另一组实验中，1μM、10μM、100μM TBN同样以浓度依赖性方式减小If电流，其[IC50]值为17.20±1.1μmol/L，希尔系数为1.01±0.4。此外，在家兔窦房结动作电位实验中，100μMTMP使家兔窦房结细胞动作电位（Action potential, AP）4期自动去极化速率（phase-4spontaneous depolarization rate，DDR）由正常的19.53±1.2mV/s减小到13.79±1.0mV/s，而100μM TBN可使DDR从正常的21.16±1.4mV/s减少到7.10±1.9mV/s。为了进一步证实TBN强大的抗氧化作用，我们在窦房结AP实验中预先给予100μM过氧化氢（H2O2）灌流，然后分别加入100μM TMP和100μM TBN以观察其作用效果。结果显示：100μM H2O2明显加快窦房结4期DDR，，从正常的20.98±1.28mV/s和21.66±1.1mV/s增加到33.24±2.3mV/s和35.71±2.1mV/s（n=6，P0.01versus Control）。给予100μM TMP后，4期DDR从33.24±2.3mV/s降低到23.57±2.44mV/s（n=6，P0.01versus H2O2）；而100μM TBN明显减小H2O2诱导增大的4期DDR（35.71±2.1mV/s to12.27±2.23mV/s，n=6，P0.01versus H2O2）。结论：①TMP及TBN对表达在卵母细胞上HCN4参与编码的超极化激活的阳离子通道电流（If）和家兔窦房结AP DDR均有明显的抑制作用；②还可降低H2O2诱导增大的窦房结细胞4期DDR；③TBN的上述阻断效果明显强于母核结构TMP；④TBN明显抑制H2O2所致的窦性心律失常。以上实验结果提示TMP和TBN可能对原发性窦性心动过速或病理条件下诱发的窦房结性快速性心律失常有一定的临床参考价值。
[Abstract]:Aim: to investigate the effects of ligustrazine (TMP) and its nitrate derivatives on hyperpolarization-activated cyclic nucleotide gated cationic channel (hyperpolarization-activated cyclic nucleotide-gatedcation channel HCN) gene family subtype HCN4 encoded by hyperpolarization-activated cationic channel current (if) and sinoatrial node in rabbits. The effect of cellular action potential. Methods: standard bipolar voltage clamp and standard glass microelectrode technique were used to record the HCN4 channel currents expressed on Xenopus laevis oocytes and the action potential of sinoatrial node in rabbits. Results: the normal HCN4 channel current expressed on oocytes was treated with 1 渭 M 10 渭 M 10 渭 M tetramethylpyrazine (TMP), and HCN4 encoded if current was blocked in a concentration-dependent manner. The IC50 of HCN4 was 48.79 卤3.1 渭 mol / L and the Hill coefficient was 1.01 卤0.3. In another group of experiments, 1 渭 MN 10 渭 M 10 渭 M TBN also reduced the if current in a concentration-dependent manner. Its [IC50] value was 17.20 卤1.1 渭 mol / L, and the Hill coefficient was 1.01 卤0.4. In addition, in the rabbit sinoatrial node action potential experiment, the phase-4spontaneous depolarization rate of (Action potential, AP decreased from 19.53 卤1.2 MV / s to 13.79 卤1.0 MV / s, while 100 渭 M TBN decreased DDR from 21.16 卤1.4 MV / s to 7.10 卤1.9 MV / s. In order to further confirm the strong antioxidation effect of TBN, 100 渭 M hydrogen peroxide (H _ 2O _ 2) was preperfused in sinoatrial node AP experiment, and then 100 渭 M TMP and 100 渭 M TBN were added to observe its effect. The results showed that 1: 100 渭 M H 2O 2 significantly increased DDR4 from normal 20.98 卤1.28 MV / s and 21.66 卤1.1 MV / s to 33.24 卤2.3 MV / s and 35.71 卤2.1 MV / s (n ~ (6) P 0.01versus control). After 100 渭 M TMP, the DDR decreased from 33.24 卤2.3 MV / s to 23.57 卤2.44 MV / s (n ~ (6) P _ (0.01) vs H _ 2O _ 2), while 100 渭 M TBN significantly decreased the increase of H2O2 induced DDR (35.71 卤2.1 MV / s to12.27 卤2.23 MV / s ~ (6) P _ (0.01versus) H _ 2O _ 2). Conclusion both TMP and TBN can inhibit HCN4 encoded hyperpolarization-activated cationic channel current (if) in oocytes and rabbit sinoatrial node AP DDR significantly. 3The blocking effect of TBN was significantly stronger than that of TMP4 TBN in inhibiting sinus arrhythmias induced by H _ 2O _ 2. These results suggest that TMP and TBN may have some clinical reference value in sinoatrial node tachyarrhythmia induced by primary sinus tachycardia or pathological conditions.
【学位授予单位】：武汉科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R54

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