苄基四氢巴马汀为四氢巴马汀的衍化物，本文采用标准膜片钳全细胞记录技术，研究了苄基四氢巴马汀对豚鼠心室肌单细胞动作电位及延迟整流钾通道（Ｉｋ）两种成分（Ｉｋｓ和Ｉｋｒ）的选择性作用。结果表明：（１）３０μｍｏｌ·Ｌ－１苄基四氢巴马汀可显著延长无钙细胞外液条件下动作电位的ＡＰＤ９０（从１４３±１６ｍｓ到１８４±２１ｍｓ，Ｐ＜００１，ｎ＝５），而对ＲＰ，ＡＰＡ无明显影响，其对ＡＰＤ９０的延长作用不依赖于胞外钙。（２）苄基四氢巴马汀对延迟整流钾通道两种成分均有不同程度的阻滞作用，其阻滞Ｉｋｒ的ＩＣ５０（半数抑制浓度）为７９μｍｏｌ·Ｌ－１，阻滞Ｉｋｓ的ＩＣ５０为２２４μｍｏｌ·Ｌ－１，可见苄基四氢巴马汀对Ｉｋ的阻滞作用无选择性 Benzyltetrahydropalmatine is a derivative of tetrahydropalmatine. In this paper, standard patch-clamp whole-cell recording technique was used to study the effect of benzyltetrahydropalmatine on single-cell action potential and delayed rectifier potassium channel in guinea pig ventricular myocytes (Ik) the two components (Iks and Ikr) selective role. The results showed that: (1) 30μmol·L-1 benzyltetrahydropalmatine could significantly prolong the action potential of APD90 without calcium extracellular fluid (from 143 ± 16ms to 184 ± 21ms, P <001, n = 5), but had no obvious effect on RP and APA, and its effect on APD90 did not depend on extracellular calcium. (2) Benzyltetrahydropalmatine blocks the two components of delayed rectifier potassium channels in varying degrees, with IC50 (half maximal inhibitory concentration) of blocking Ikr being 79μmol·L-1 and blocking Iks The IC50 was 224μmol·L-1, showing that benzyltetrahydropalmatine had no selectivity for Ik blockade