摘要
目的研究血管紧张素Ⅱ(AngⅡ)和替米沙坦对SD大鼠心房肌细胞瞬时外向钾电流(Ito)和L型钙电流(ICa-L)的作用。方法急性酶解法分离SD大鼠心房肌细胞,采用全细胞膜片钳技术,观察AngⅡ、替米沙坦以及AngⅡ联合替米沙坦对大鼠心房肌细胞Ito和ICa-L的影响。结果 AngⅡ(0.1μmol/L)和替米沙坦(0.01μmol/L)以及两药联合均能抑制大鼠心房肌细胞Ito,AngⅡ组、替米沙坦组、联合组干预前后Ito的电流密度值比较差异有统计学意义[(22.48±2.75)vs(15.71±2.06)pA/pF,(24.16±2.36)vs(16.15±1.82)pA/pF,(24.41±2.27)vs(21.35±1.46)pA/pF,P<0.05]。AngⅡ(0.1μmol/L)能显著增强大鼠心房肌细胞ICa-L的峰值电流密度[(-4.51±0.38)vs(-5.16±0.29)pA/pF,P<0.01];替米沙坦(0.01μmol/L)对心房肌细胞ICa-L无明显作用[(-4.35±0.27)vs(-4.29±0.34)pA/pF,P>0.05],但联合组中替米沙坦可拮抗AngⅡ对ICa-L的增强效应[(-4.08±0.28)vs(-4.20±0.31)pA/pF,P>0.05]。结论 AngⅡ和替米沙坦对大鼠心房肌细胞具有直接的电生理作用,替米沙坦在受体水平上存在对AngⅡ的拮抗效应。
Objective To study the effect of angiotensinⅡ（AngⅡ） and telmisartan on transient outward potassium and calcium current in atrial myocytes of Sprague-Dawley（SD） rats.Methods Atrial myocytes were isolated from SD rats with the enzymatic dissociation method.Effect of AngⅡ,telmisartan and conbined AngⅡand telmisartan on transient outward potassium and calcium current in atrial myocytes of SD rats was observed with the whole cell patch-clamp recording technique.Results AngⅡ（0.1 μmol/L）,telmisartan（0.01 μmol/L）,and combined AngⅡ and telmisartan inhibited the outward potassium current.The peak outward potassium current density was 22.48±2.75 vs 15.71±2.06 pA/pF,24.16±2.36 vs 16.15±1.82 pA/pF,and 24.41±2.27 vs 21.35±1.46 pA/pF,respectively（P〈0.05）,in AngⅡgroup,telmisartan group,and combined AngⅡand telmisartan group.AngⅡ（0.1 μmol/L） significantly increased the peak calcium current density in atrial myocytes of rats（-4.51±0.38 vs-5.16±0.29 pA/pF,P〈0.01）.Telmisartan（0.01 μmol/L） had no significant effect on the peak calcium current density in atrial myocytes of rats（-4.35±0.27 vs-4.29±0.34 pA/pF,P〉0.05）.However,it could antagonize the effect of AngⅡon the peak calcium current density in combined AngⅡ and telmisartan group（-4.08±0.28 vs-4.20±0.31 pA/pF,P〉0.05）.Conclusion AngⅡand telmisartan can exert their direct electrophysiological effects on atrial myocytes of rats,while telmisartan can antagonize the effect of AngⅡon the peak calcium current density at angiotensin receptor level.
出处
《第三军医大学学报》
CAS
CSCD
北大核心
2011年第12期1228-1232,共5页
Journal of Third Military Medical University
基金
国家自然科学基金(30871075)~~
关键词
血管紧张素Ⅱ
抗心律失常药
钾通道
心肌
膜片钳技术
L型钙电流
大鼠
angiotensinⅡ
anti-arrhythmia agent
potassium channels
myocardium
patch-clamp techniques
L-type calcium current
rats
