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Electrophysiology of Irbesartan in guinea pig ventricular myocytes
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- Author:
- No author available
- Journal Title:
- JOURNAL OF THE FOURTH MILITARY MEDICAL UNIVERSITY
- Issue:
- 1
- DOI:
- 10.3321/j.issn:1000-2790.2005.01.005
- Key Word:
- 厄贝沙坦;心肌;钙通道;膜片钳术;电生理学
Abstract： 目的:研究厄贝沙坦(Irbesartan)对正常豚鼠心室肌细胞L-型钙电流(ICa-L)、内向整流性钾电流(IK1)、快钠流(INa)以及跨膜动作电位的影响.方法:应用膜片钳全细胞记录方法记录各项离子流和跨膜动作电位.结果:①厄贝沙坦呈浓度依赖性阻断ICa-L,10,100和1000 nmol/L的厄贝沙坦分别使ICa-L密度 (pA/pF)从 (-9.8±1.1)减少到(-6.7±0.9),(-4.2±0.8)和(-2.1±0.4)(n=5,P<0.05或P<0.01).②厄贝沙坦可使ICa-L I-V曲线上移,但不改变其激活的电压依赖性和反转电位.③厄贝沙坦呈使用依赖性阻滞ICa-L.④厄贝沙坦对ICa-L激活曲线无明显影响,但可使钙电流稳态失活曲线左移,加速钙通道电压依赖性失活,对照组V1/2和κ值分别为(-30±5)mV,(8.2±0.7),厄贝沙坦组为(-39±7) mV,(11.6±1.3)(n=5,P均<0.05).⑤厄贝沙坦100 nmol/L使ICa-L失活后再激活的恢复时间常数(τ)从对照组(62.5±2.3) ms延长至(126.4±2.6) ms(P<0.01).⑥厄贝沙坦对IK1和INa无明显影响.⑦厄贝沙坦(100 nmol/L)可使单个心室肌细胞动作电位时程(APD30,APD50,APD90)从(106±10),(125±16),(178±23)ms缩短至(82±16),(99±6),(122±18) ms(n=5,P<0.05),对静息电位、动作电位幅度无影响. 结论:厄贝沙坦作用于L-型钙通道的失活态从而阻断ICa-L.
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