MN9202对心肌细胞的收缩和舒张功能的影响

Effects of MN9202 on contraction and relaxation functions of cardiac myocytes

目的研究MN9202对心肌细胞收缩舒张功能的影响。方法采用IonOptix单细胞动缘检测系统(IonOptixCo.USA),测定心肌细胞收缩幅度和收缩/舒张速度等,这些指标均由计算机自动实时采集并记录。结果MN9202降低心肌收缩幅度(ph)、心肌细胞收缩幅度单个心肌细胞的长度百分比(peakheightbaseline×100%,phbl%)、最大收缩速率(+dLdt)和最大舒张速率(dLdt),ph在对照组、MN9202(3×106molL)组和拉西地平(lacidipine,3×106molL)组分别为(0.13±0.04)μm、(0.08±0.05)μm和(0.07±0.04)μm,phbl%分别为(8.6±2.8)%、(5.8±4.3)%和(5.6±3.3)%,+dLdt分别为(1.6±0.5)μms、(1.1±0.7)μms和(1.0±0.6)μms,dLdt分别为(1.2±0.4)μms、(0.8±0.3)μms和(0.7±0.3)μms。异丙肾上腺素(108molL,isoproterenol,Iso)增加ph、phbl%、+dLdt和dLdt均有统计学意义,上述指标分别增加45%、47%、54%、78%。3×107molL的MN9202和拉西地平降低Iso引起ph、phbl%、+dLdt和dLdt的升高,其中MN9202使+dLdt和dLdt的降低较对照组有显著差异(P<0.05),拉西地平使phbl%、+dLdt和dLdt的降低较对照组有统计学意义。结论MN9202使心肌细胞收缩和舒张功能均降低;Iso所致心肌细胞收缩和舒张功能的增强,3×107molLMN9202和拉西地平有抑制Iso的作用。

Objective To investigate the effect of MN9202 on contraction and relaxation functions of cardiac myocytes. Methods The contraction amplitude was measured with video edge tracker method. The following indexes including contraction amplitude (ph), contraction amplitude/single cardiac myocyte length percent(ph/bl%), maximal velocity of contraction (+d L /d t ) and maximal velocity of relaxation (-d L /d t )were recorded by the computer. Results MN9202 and lacidipine decreased electrically-induced contraction and ph,ph/bl%,+d L /d t and -d L /d t . MN9202 and lacidipine at dose of 3×10 -6 mol/L attenuated these indexes significantly. Compared with the control group, MN9202(3×10 -6 mol/L) decreased ph from (0.13± 0.04) μm to (0.08±0.05) μm,ph/bl% from(8.6%±2.8% )to (5.8%±4.3%),+d L /d t from (1.6±0.5)μm/s to (1.1± 0.7)μm/s, -d L /d t from (1.2±0.4)μm/s to (0.8±0.3)μm/s. lacidiipine at dose of 3×10 -6 mol/L decreased ph from (0.13 ±0.04)μm to (0.07±0.04)μm,ph/bl% from (8.6%±2.8%) to (5.6%±3.3%),+d L /d t from (1.6±0.5)μm/s to (1.0± 0.6)μm/s, -d L /d t from (1.2±0.4)μm/s to (0.7±0.3)μm/s. Isoproterenol (Iso) at 10 -8 mol/L augmented electrically-induced contraction and ph,ph/bl%, +d L /d t and -d L /d t . These indexes increased by 45%,47%,54%,78% respectively. The effect of Iso (10 -8 mol/L) was reduced by MN9202 and lacidipine at dose of 3×10 -7 mol/L. Conclusion MN9202 and LDH attenuated contraction and relaxation functions of cells, while Iso increased contraction and relaxation functions of cells. The effects of Iso (10 -8 mol/L) were inhibited by MN9202 and lacidipine at dose of 3×10 -7 mol/L.