中文摘要：

目的：研究慢性激活天门冬氨酸（NMDA）受体对大鼠离体心脏电整复性（APDR）和室性心律失常的影响。方法：将36只雄性Wistar大鼠随机平均分为对照组（CTL组）、NMDA激活组（N组）、NMDA抑制组（M组）,经腹腔分别注射生理盐水（1ml/kg）、NMDA（2mg/kg）、NMDA（2mg/kg）＋MK-801（0.5mg/kg）,连续14d;结束后7d内,在Langendorff灌流条件下行离体心脏电生理研究,记录和测量左室前游离壁（LAF）的单向动作电位（MAP）及有效不应期（ERP）,并绘制电整复性曲线,计算曲线最大斜率（Smax）;运用Burst法刺激诱发室性心律失常。结果：N组大鼠左心室90%的复极时间（MAPD90）和APDR曲线最大斜率（Smax）均较CTL组和M组大（P〈0.01）;N组大鼠左心室ERP和ERP/MAPD90均较CTL组和M组小（P〈0.01）;N组大鼠室性心律失常的诱发率均高于CTL组和M组（P〈0.01）。结论：慢性激活NMDA受体延长了心室可激动时间,增加了左心室复极离散度,从而容易诱发室性心律失常。

英文摘要：

Objective. To assess the effect of NMDA receptor on action potential duration restitution （APDR） and ventricular arrhythmogensis in rat heart. Methods. Thirty-six male rats were ran- domly divided into three groups, control group （CTL group）, NMDA agonist group （N group） and NMDA inhibitor MK-801（M group）, then received intraperitoneal injection of saline （1 ml/ kg）, NMDA （2 mg/kg） and NMDA （2 mg/kg） ＋ MK-801 （0. 5 mg/kg） for 14 consecutive days, respectively. After seven days, in the Langendorff perfusion conditions, monophonic action potential （MAP） and effective refractory period （ERP） of left ventricular free wall （LAF） were measured, and the whole repolarization curve was drawn. Ventricular arrhythmia （VA） was in- duced by Burst stimulus on LAF. Results. Compared to CTL group and M group, the 90% of MAP duration （MAPDg0） and Smax were significantly increased （P〈0.01）, the ERP and ERP/ MAPD90 were significantly shortened （P%0.01）, and the induction rate of ventricular arrhythmia were higher in N group. Conclusion： Chronic stimulation with NMDA facilitates VA, possibly through increasing excited duration and dispersion of APD restitution.