心肌肽素对豚鼠和大鼠心室肌细胞的电生理作用

发布时间：2018-03-07 05:16

本文选题：心肌肽素　切入点：心室肌细胞　出处：《中国协和医科大学》2005年博士论文　论文类型：学位论文

【摘要】：心肌肽素对豚鼠和大鼠心室肌细胞的电生理作用目的：研究心肌肽素对豚鼠和大鼠心室肌细胞的L-型钙通道、钠通道和钾通道电流的影响，探讨心肌肽素在离子通道水平的药理作用机制。方法：用急性酶解法分离获得单个豚鼠和大鼠心室肌细胞。用标准的全细胞膜片钳技术记录各种离子通道电流，观察不同浓度的心肌肽素对豚鼠心室肌细胞L-型钙电流(I_(Ca-L))、钠电流(I_(Na))、内向整流钾电流(I_(K1))的影响，及大鼠心室肌细胞I_(K1)和和瞬时外向钾电流(I_(to))的影响。结果：通过酶解法得到的豚鼠和大鼠心室肌细胞能够记录到动作电位和各种离子通道电流。表明其具有良好的细胞电生理特性。在测试电压+10 mV的条件下，心肌肽素1、5、10、50、100、500 mg／L浓度依赖性增强豚鼠心室肌细胞I_(Ca-L)，使I_(Ca-L)分别增加(5±4)％、(21±5)％、(30±5)％、(55±8)％、(76±11)％、(88±14)％，半最大有效浓度(EC_(50))为(18±6)mg／L。心肌肽素50 mg／L使激活时间(TTP)从(6.7±0.9)ms缩短为(5.9±0.7)ms(P＜0.01)。心肌肽素50 mg／L使I_(Ca-L)电流密度-电压曲线下移，但激活电位、峰电位和I-V曲线的形状不变。心肌肽素50 mg／L使激活曲线向负电位方向变化，半数激活电压从(-4.3±0.4)mV减少至(-8.6±0.4)mV(P＜0.05)，不影响稳态失活曲线和稳态失活后恢复曲线。在测试电压-20 mV的条件下，心肌肽素1、5、10、50、100、500 mg／L浓度依赖性抑制豚鼠心室肌细胞I_(Na)，使I_(Na)分别抑制(0±1)％、(6±2)％、(10±2)％、(15±1)％、(22±9)％、(30±6)％。心肌肽素50 mg／L使I_(Na)TTP从(2.8±0.7)ms延长至(3.0±0.8)ms(P＜0.05)。心肌肽素50 mg／L使I_(Na)电流密度-电压曲线上移，但不改变激活电位、峰电位、反转电位和I-V曲线的形状。心肌肽素50 mg／L不影响稳态激活曲线、稳态失活曲线和稳态失活后恢复曲线。 I_(K1)内向和外向电流分别以测试电压-100 mV和-30 mV条件下的稳态电流作为观察指标。心肌肽素10、50 mg／L分别使豚鼠心室肌细胞抑制(24±7)％、(32±6)％，，而心肌肽素100、500 mg／L分别使豚鼠心室肌细胞I_(K1)内向电流增加(22±11)％、(357±43)％。心肌肽素10 mg／L使大鼠心室肌细胞I_(K1)内向电流抑制(33±7)％，而心肌肽素100、250、500 mg／L分别使大鼠心室肌细胞I_(K1)内向电流增加(18±5)％、(134±24)％、(292±66)％。所有浓度的心肌肽素对I_(K1)外向电流无明显影响。心肌
[Abstract]:Electrophysiological effects of cardiopeptide on ventricular myocytes in guinea pigs and rats. Aim: to study the effects of cardiopeptidin on the currents of L-type calcium channel, sodium channel and potassium channel in guinea pig and rat ventricular myocytes, and to explore the pharmacological mechanism of cardiopeptide at ion channel level. Methods: single guinea pig and rat ventricular myocytes were isolated by acute enzymolysis, and various ion channel currents were recorded by standard whole-cell patch clamp technique. To observe the effects of different concentrations of cardiopeptidin on L- type calcium current in guinea pig ventricular myocytes (I + Ca-L), sodium current (I), inward rectifier potassium current (I + K ~ (1)), and rat ventricular myocytes (I _ (+) K _ (1)) and transient outward potassium current (I _ (+))). Results: the action potential and various ion channel currents were recorded in guinea pig and rat ventricular myocytes by enzymatic hydrolysis. At a test voltage of 10 MV, Cardiopeptidin 1 51050 / 100 mg/L in a concentration-dependent manner enhanced the activity time of guinea pig ventricular myocytes in a concentration-dependent manner, resulting in an increase of 5 卤4 Ca-L, respectively, and an increase of 5 卤4 Ca-L1, respectively. Myocardial peptide 50 mg/L reduced the current density to voltage curve of IZL from 6. 7 卤0. 9ms to 5 卤0. 7MSP < 0. 01. Cardiopeptide 50 mg/L reduced the current density-voltage curve of Iatrophin to 5 卤6mg / L in a concentration-dependent manner. The activation time was shortened from 6. 7 卤0. 9 Ms to 5.9 卤0. 7 Ms P < 0. 01. Cardiopeptide 50 mg/L decreased the current density-voltage curve of Iatropium sinensis, and decreased the activation time from 6. 7 卤0. 9 Ms to 5 卤0. 7 Ms P < 0. 01, respectively, and decreased the activity time from 6. 7 卤0. 9 Ms to 5 卤0. 01 mg/L. But the shape of activation potential, peak potential and I-V curve were unchanged. Cardiopeptide 50 mg/L changed the activation curve to negative potential, and the half activation voltage decreased from -4.3 卤0.4mV to -8.6 卤0.4mV (P < 0.05), which did not affect the steady-state inactivation curve and the recovery curve after steady-state inactivation. Under the test voltage of -20 MV, cardiopeptidin 1 5 01050 / 100 mg/L in a concentration-dependent manner inhibited Igna Na (P < 0 05) in guinea pig ventricular myocytes. It inhibited 0 卤1 1 + 10 卤2 G + 10 卤2 G + 10 卤2 + 10 卤20 MV, respectively, and increased the current density curve of IPS from 2. 8 卤0. 7ms to 3. 0 卤0. 8ms P < 0. 05. Cardiopeptigenin 50 mg/L increased the current density curve of Iapeptide from 2. 8 卤0. 7ms to 3. 0 卤0. 8ms P < 0. 05. Cardiopeptide 50 mg/L increased the current density curve of Iapeptidine, and increased the current density curve of myopeptidin 50 in guinea pig ventricular myocytes from 2. 8 卤0. 7 Ms to 3. 0 卤0. 8 Ms P < 0. 05. The current density curve of myopeptide 50 was increased. But the shape of activation potential, peak potential, reverse potential and I-V curve were not changed. Cardiopeptide 50 mg/L had no effect on steady-state activation curve, steady-state inactivation curve and steady-state inactivation curve. The steady-state currents at the test voltages of -100mV and -30mV were used to observe the inward and outward currents, respectively. Cardiopeptidin 1050 mg/L inhibited ventricular myocytes of guinea pig by 24 卤7 ~ 2 卤6 ~ 5%, respectively, while cardiopeptide 100,500 mg/L made guinea pig ventricular muscle fine, respectively. Cardiac peptide 10 mg/L inhibits the inward current of rat ventricular myocytes by 33 卤7%, while cardiopeptidin 100,250,500 mg/L increases the inward current of rat ventricular myocytes by 18 卤5 1 卤2 4 卤6 6. All concentrations of cardiopeptide have a positive effect on Imik 1. There is no obvious effect on the flow.
【学位授予单位】：中国协和医科大学
【学位级别】：博士
【学位授予年份】：2005
【分类号】：R33

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