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目的 观察葡萄糖对豚鼠心室肌细胞膜APD ,IK1 ,IK ,ICa L的影响。方法 采用全细胞膜片技术记录单个豚鼠心室肌细胞膜的动作电位时程和离子电流。比较 0、10和 2 0mmol·L 1 葡萄糖对心室肌细胞跨膜离子电流的作用。结果 (1)与10mmol·L- 1 葡萄糖相比 ,0和 2 0mmol·L- 1 均可使豚鼠心室肌细胞的APD缩短 (P <0 0 5 ) ;(2 )在细胞外葡萄糖浓度为 10mmol·L- 1 时 ,内向整流钾电流IK1 的电流密度最大 ,标准化I-V曲线显示 0和 2 0mmol·L- 1 葡萄糖均可抑制IK1 ,并使I -V曲线左移 ,其翻转电位从 - 72 4移至 - 6 4 6mV ;(3)与mmol·L- 1 葡萄糖相比 ,0和 2 0mmol·L- 1 葡萄糖均可增加ICa L的电流幅度和电流密度。当钳制电位为 10mV ,细胞外葡萄糖浓度为 0mmol·L- 1 时 ,ICa L的电流密度为 (- 8 0 3± 0 82 )pA pF (n =8) ,而 10mmol·L- 1 和 2 0mmol·L- 1 葡萄糖分别使电流密度增加为 (- 5 4 5± 0 6 7)pA pF和 (- 6 5 0± 0 5 6 )pA pF ;(4 )当钳制电压为 +70mV ,细胞外葡萄糖浓度为 0、10和 2 0mmol·L- 1 时 ,IK 的电流密度分别为 (18 96± 2 86 )pA pF ,(8 6 6± 1 87)pA pF ,(15 32± 3 12 )pA pF。结论 细胞外不同浓度的葡萄糖可使豚鼠心室肌细胞APD ,IK1 ,IK ,ICa L发生改变。细?
Objective To observe the effect of glucose on APD, IK1, IK and ICa L of guinea pig ventricular myocytes. Methods Whole cell patch technique was used to record the action potential duration and ion current of single guinea pig ventricular myocytes. The effects of 0, 10 and 20 mmol·L 1 glucose on the transmembrane ion current of ventricular myocytes were compared. Results (1) Compared with 10 mmol·L-1 glucose, APD of guinea pig ventricular myocytes was shortened by 0 and 20 mmol·L-1 (P <0.05). (2) When the extracellular glucose concentration was 10 mmol · L-1, the current density of IK1 was the largest. The normalized IV curve showed that 0 and 20 mmol·L-1 glucose could inhibit IK1 and left I-V curve to the left. The inversion potential was -72 (3) Compared with mmol·L-1 glucose, both 0 and 20 mmol·L-1 glucose increased the ICa L current amplitude and current density. When the clamp potential was 10 mV and the extracellular glucose concentration was 0 mmol·L-1, the current density of ICa L was (-803 ± 0 82) pA pF (n = 8), while the concentration of 10 mmol·L-1 and 20 mmol L-1 glucose increased the current density to (- 545 ± 0 6 7) pA pF and (-650 ± 0 5 6) pA pF, respectively; (4) When the clamp voltage was +70 mV, extracellular glucose The current densities of IK were (18 96 ± 2 86) pA pF, (866 ± 1 87) pA pF and (15 32 ± 3 12) pA pF at concentrations of 0, 10 and 20 mmol·L- . Conclusion Different concentrations of extracellular glucose can change the APD, IK1, IK and ICa L in guinea pig ventricular myocytes. fine?