【摘要】 目的 :利用单相动作电位 ( MAP)技术研究在整体条件下四氢巴马汀对家犬心室肌 MAP时程的使用依赖性。方法 :同时记录家犬 ( 12只 )右室心尖部的 MAP和体表标准 II导联心电图 ,比较给药前后和在窦性心律以及 2 3 0、2 60、2 90、3 2 0次 /min起搏频率下心室肌有效不应期 ( ERP)、MAP复极 5 0 % ( MAPD50 )和复极 90 %( MAPD90 )的变化。结果 :给药 3 0 min( 2 0 m g/kg)后 ,在同一起搏频率下 ,ERP、MAPD50 、和 MAPD90 均明显延长 ,与给药前相比差异有极显著性意义 ( P <0 .0 1) ;随起搏频率增加 ,ERP、MAPD50 和 MAPD90 逐渐缩短 ,但比较给药后不同起搏频率与窦性心律时的 ERP、MAPD50 和 MAPD90 变化率以及 ERP/MAPD90 比值的变化 ,则差异无显著性意义 ( P >0 .0 5 )。结论 :在整体条件下 ,四氢巴马汀无逆向使用依赖性。更多还原

【Abstract】 Objective: The technique of monophasic action potential (MAP) was utilized to study the use dependent of the duration of MAP in 12 canines. Method: The MAP of the tip of right ventricule and surface lead Ⅱ electrocardiogram (ECG) were simultaneously recorded. The effective refractory period (ERP) and duration of MAP at 50% (MAPD 50 ) and at 90% (MAPD 90 ) were measured during sinus rhythm and at pacing rate of 230, 260, 290 and 320 beat per minute. The changes of ERP and duration of MAP were assessed before and at 30 minutes after administration of THP 20 mg/kg.Result: At the same pacing rate, compared with those before using tetrahydropalmatine (THP). ERP, MAPD 50 and MAPD 90 were significantly prolonged (P< 0.01 ) 30 minutes after the administration of THP.The ERP, MAPD 50 and MAPD 90 gradually shortened with pacing rate increasing as compared with those in sinus rhythm. However, the variable rate of them and the rate of ERP to MAPD 90 had no significantly variance (P> 0.05 ).Conclusion: In vivo, THP has no reverse use dependent effect.更多还原