尼美舒利对豚鼠心乳头肌动作电位和收缩力的影响

Effect of Nimesulide on action potential and contraction force of guinea pig papillary muscles

目的观察尼美舒利(Nim)与吡那地尔(Pin)对豚鼠心乳头肌动作电位和收缩力的影响。方法选取华中科技大学同济医学院实验动物学部提供的符合实验标准的健康豚鼠54只,将其随机分为6组,溶剂对照组(DMSO组)、Pin 1μmol/L组、Pin 10μmol/L组、Nim 1μmol/L组、Nim 3μmol/L组、Nim 10μmol/L组,每组各9只豚鼠。每组取豚鼠右心室乳头肌,用氧饱和的Tyrode液30 m L持续表面灌流,温度(37±1)℃,平衡30 min后进行实验,分别用不同浓度的Nim(1、3、10μmol/L)和Pin(1、10μmol/L)进行灌流。用标准微电极技术记录豚鼠心乳头肌细胞动作电位复极20%(APD20)、复极50%(APD50)、复极90%(APD90)的时间,同步记录乳头肌收缩力。再用无药台氏液冲洗120 min,观察结果。结果 Nim 3μmol/L、Nim 10μmol/L和Pin 10μmol/L可显著缩短豚鼠心乳头肌细胞APD20、APD50、APD90的时间。二者对0相最大上升速度和收缩力均无明显影响。用无药台氏液冲洗120 min后,被Nim缩短的动作电位时程可恢复至给药前水平。结论 Nim可显著缩短豚鼠心乳头肌动作电位时程,且此效应可逆,对收缩力无影响。

Objective To investigate the effect of Nimesulide（Nim） and pinacidil（Pin） on action potential and contractile force of guinea pig papillary muscles. Methods 54 guinea pigs of experimental standard were selected from Department of Laboratory Animal in Tongji Medical College, they were randomly divided into six groups, the solvent control group（DMSO group）, Pin 1 μmol/L group, Pin 10 μmol/L group, Nim 1 μmol/L, Nim group 3 μmol/L group, Nim 10μmol/L group, and 9 guinea pigs in each group. Each guinea pig papillary muscle were provided with 30 m L oxygensaturated Tyrode, the temperature was（37±1）℃, continuous superfusion, after equilibration experiments for 30 min, the muscles were perfused with different concentrations of Nim（1, 3, 10 μmol/L） and Pin（1, 10 μmol/L）. The time of repolarization 20%（APD20）, repolarization of 50%（APD50）, repolarization of 90%（APD90） about the action potential duration（APD） of guinea pig papillary muscles were recorded by standard microelectrode, and muscle contractile force were recorded at the same time. The non-drug-tyrode was washed for 120 min and the results were observed. Results The results showed that Nim 3, 10 μmol/L and Pin 10 μmol/L can significantly shorten the time of APD20, APD50, APD90 of the guinea pig papillary muscle cell. Both the contractile force and maximum velocity had no significant influence. After non-drug-tyrode for 120 min, APD was recovered to the level before administration. Conclusion Nim can significantly shorten APD of guinea pig papillary muscles, and the effect is reversible, and has no effect on the contraction.