3,6-二甲氨基-二苯骈碘因甲酸盐对豚鼠单—心室肌细胞动作电位和慢内向钙电流的影响

EFFECTS OF 3,6-DIMETHYLAMINO-DIBENZOPYRIODONIUM FORMIATE ON ACTION POTENTIAL AND SLOW INWARD CALCIUM CURRENT IN ISOLATED GUINEA PIG VENTRICULAR MYOCYTES

摘要: 采用全细胞电压钳技术,观察了3,6-二甲氨基-二苯骈碘因甲酸盐(IHC-64)对豚鼠单一心室肌细胞动作电位和慢内向钙电流(I_si)的影响。结果表明,IHC-64 20和200 μmol/L可明显缩短APD₂₀和APD₉₀。予先给予钙通道阻滞剂尼索地平可取消IHC-64缩短APD₂₀的作用。在电压钳条件下,上述浓度的IHC-64对I_si有明显的抑制作用,I_si由给药前的1.92±0.41 nA分别降低至给药后1.73±0.50 nA(P<0.05)和0.62±0.38 nA(P<0.01).提示IHC-64可能对心肌细胞钙通道有阻滞作用。

Abstract: The effects of 3, 6-dimethylamino-dibenzopyriodonium formiate (IHC-64) on action potential and slow inward calcium current (I_si) were investigated in isolated guinea pig ventricular myocytes using whole cell voltage clamp recording. IHC-64 (20 and 200 μmol/L) was shown to markedly decrease APD₂₀ and APD₉₀. However, in the presence of nisoldipine, no obvious effects of IHC-64 on APD₂₀ could be detected. Under voltage clamp conditions, IHC-64 (20 and 200 μmol/L) caused a significant decrease in I_si. The results indicate that IHC-64 can block the calcium channels in isolated guinea pig ventricular myocytes.