摘要:
目的:研究阻断Ryanodine受体对兔心肌肥厚触发性室性心律失常发生的影响。方法:选择日本长耳兔,通过缩窄腹主动脉建立心肌肥厚模型（LVH组）,并设立假手术组（仅游离腹主动脉,不进行缩窄）作为对照。8周后应用超声心动图证实心肌肥厚形成,采用酶解法分离左室心肌细胞,应用全细胞膜片钳技术记录动作电位,观察在异丙肾上腺素（1μmol/L）灌流和快频率（5Hz）电刺激条件下,单个心肌细胞晚期后除极（DAD）和触发活动的发生率,以及预先分别灌流钙调蛋白激酶Ⅱ抑制剂KN-93（1μmol/L）和Ryanodine受体阻滞剂兰尼碱（10μmol/L）对肥厚心肌细胞DAD和触发活动发生率的影响。结果:假手术组、LVH组、KN-93组和兰尼碱组DAD的发生率分别为0、85%、35%和20%,触发活动的发生率分别为0、60%、20%和10%,KN-93组和兰尼碱组DAD和触发活动的发生率较LVH组显著降低（P<0.05）。结论:阻断Ryanodine受体能够有效抑制兔心肌肥厚触发性室性心律失常的发生,Ryanodine受体有望成为防治该类心律失常的新靶点。
Abstract:
Objective:To investigate the effect of Ryanodine receptor blockage on triggered ventricular arrhythmia in rabbits with left ventricular hypertrophy（LVH）.Method:Japanese rabbits were established LVH models by the coarctation of the abdominal aorta,while those in the sham group did not undergo the coarctation.After 8 weeks,single left ventricular myocyte was isolated by enzymatic dissociation method and action potential（AP） was recorded using whole cell patch clamp technique.Perfused with Tyrode's solution containing isoprenaline（1 μmol/L）,the frequency of delayed afterdepolarization（DAD） and triggered activity was recorded under high-frequency stimulation stimulation（5 Hz）.And the effect of KN-93 and Ryanodine perfusion on the frequency of DAD and triggered activity was observed.Result:The frequency of DAD was 0 in sham group,85% in LVH group, 35% in KN-93 group,and 20% in Ryanodine group.The frequencies of triggered activity were 0,60%,20%,and 10%,respectively.The frequencies of DAD and triggered activity in KN-93 and Ryanodine groups were much lower than those in LVH group（P<0.05）.Conclusion:Blockage of Ryanodine receptor is a new method of treatment which effectively reduce the occurrence of triggered ventricular arrhythmia in rabbits with LVH.
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