胰岛素对家兔右室心肌细胞L型钙电流的影响
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摘要
目的研究不同浓度胰岛素对家兔右室心肌细胞L型钙电流(ICa-L)的影响。方法采用膜片钳技术记录家兔右室心肌的ICa-L,予150、400和1 000 pmol/L胰岛素干预后记录ICa-L的变化。结果 150、400和1 000 pmol/L胰岛素使ICa-L峰值由(5.92±0.53)p A/p F减至(4.71±0.12)、(3.31±0.39)和(1.83±0.22)p A/p F(n=8,P<0.01);胰岛素使ICa-L的电流-电压曲线上移,但不改变其激活电位、电位峰值和反转电位。结论胰岛素对家兔右室心肌细胞ICa-L具有阻滞作用。这可能是胰岛素引起某些心律失常的重要机制。
Objective To investigate the effects of different concentrations of insulin on L-type calcium current in rabbit's right ventricle. Methods The myocytes were obtained by enzyme digestion from right walls of rabbits. L-type calcium current were recorded under different concentrations of insulin by whole-cell patch-clamp technique. Results According to current clamp protocol,L-type calcium currents affected by different concentration insulin were significantly different. 150,400,1 000 pmol / L insulin significantly decreased the peak of L-type calcium from( 5. 92 ± 0. 53) p A / p F to( 4. 71 ± 0. 12),( 3. 31 ± 0. 39) and( 1. 83 ± 0. 22) p A /p F respectively. Insulin upshifted the I-Vcurves of L-type calcium without changes of their active,peak and reverse potentials. Conclusions Insulin has different effects on L-type calcium current of the rabbit's right ventricle myocytes,which could be one of the mechanisms of ventricular arrhythmia after meal.
Objective To investigate the effects of different concentrations of insulin on L-type calcium current in rabbit's right ventricle. Methods The myocytes were obtained by enzyme digestion from right walls of rabbits. L-type calcium current were recorded under different concentrations of insulin by whole-cell patch-clamp technique. Results According to current clamp protocol,L-type calcium currents affected by different concentration insulin were significantly different. 150,400,1 000 pmol / L insulin significantly decreased the peak of L-type calcium from( 5. 92 ± 0. 53) p A / p F to( 4. 71 ± 0. 12),( 3. 31 ± 0. 39) and( 1. 83 ± 0. 22) p A /p F respectively. Insulin upshifted the I-Vcurves of L-type calcium without changes of their active,peak and reverse potentials. Conclusions Insulin has different effects on L-type calcium current of the rabbit's right ventricle myocytes,which could be one of the mechanisms of ventricular arrhythmia after meal.
引文
1 Nishizaki M,Sakurada H,Mizusawa Y,et al.Influence of meals on variations of ST segment elevation in patients with brugada syndrome[J].Journal of Cardiovascular electrophysiology,2008,19:62
2 Ikeda T,Abe A,Yusu S,et al.The full stomach test as a novel diagnostic technique for identifying patients at risk of Brugada syndrome[J].Journal of Cardiovascular Electrophysiology,2006,17(6):602
3 谢强,张紫冠,李卫华,等.胰岛素对家兔右室各层细胞动作电位的影响[J],中国心脏起搏与心电生理杂志,2010,24(5):442
4 Idriss SF,Wolf PD.Transmural action potential repolarization heterogeneity develops postnatally in the rabbit[J].Journal of Cardiovascular Electrophysiology,2004,15(7):7955万军,黄从新,王腾.家兔心室肌各层细胞的动作电位及瞬间外向钾电流特性[J].中国心脏起搏与心电生理杂志,2001,15(1):25
6 Hamill OP,Marty A,Neher E,et al.Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches[J].1981,391(2):85
7 Nishizaki M,Sakurada H,Ashikaga T,et al.Effects of glucose-induced insulin secretion on ST segment elevation in the Brugada syndrome[J].Cardiovasc Electrophysiol,2003,14(3):24
8 Nogami A,Nakao M,Kubota S,et al.Enhancement of J-ST-segment elevation by the glucose and insulin test in Brugada syndrome[J].Pacing Clin Electrophysiol,2003,26(1 Pt 2):332
9 Nishizaki M,Sakurada H,Mizusawa Y,et al.Influence of meals on variations of ST segment elevation in patients with brugada syndrome[J].Journal of Cardiovascular Electrophysiology,2008,19(1):62
2 Ikeda T,Abe A,Yusu S,et al.The full stomach test as a novel diagnostic technique for identifying patients at risk of Brugada syndrome[J].Journal of Cardiovascular Electrophysiology,2006,17(6):602
3 谢强,张紫冠,李卫华,等.胰岛素对家兔右室各层细胞动作电位的影响[J],中国心脏起搏与心电生理杂志,2010,24(5):442
4 Idriss SF,Wolf PD.Transmural action potential repolarization heterogeneity develops postnatally in the rabbit[J].Journal of Cardiovascular Electrophysiology,2004,15(7):7955万军,黄从新,王腾.家兔心室肌各层细胞的动作电位及瞬间外向钾电流特性[J].中国心脏起搏与心电生理杂志,2001,15(1):25
6 Hamill OP,Marty A,Neher E,et al.Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches[J].1981,391(2):85
7 Nishizaki M,Sakurada H,Ashikaga T,et al.Effects of glucose-induced insulin secretion on ST segment elevation in the Brugada syndrome[J].Cardiovasc Electrophysiol,2003,14(3):24
8 Nogami A,Nakao M,Kubota S,et al.Enhancement of J-ST-segment elevation by the glucose and insulin test in Brugada syndrome[J].Pacing Clin Electrophysiol,2003,26(1 Pt 2):332
9 Nishizaki M,Sakurada H,Mizusawa Y,et al.Influence of meals on variations of ST segment elevation in patients with brugada syndrome[J].Journal of Cardiovascular Electrophysiology,2008,19(1):62