夹竹桃麻素对过氧化氢所致兔心房肌细胞超速激活延迟整流钾电流及瞬时外向钾电流异常的保护作用  被引量:4

Protective effect of apocynin on abnormalities of ultra rapid delayed rectifier potassium current and transient outward potassium current induced by hydrogen peroxide in rabbit atrial myocytes

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作  者:刘岩[1] 李泱[2] 林琨[1] 田苗[1] 王玉堂[1] 单兆亮[1] 

机构地区:[1]解放军总医院心内科,北京100853 [2]解放军总医院老年心血管病研究所,北京100853

出  处:《中国心脏起搏与心电生理杂志》2012年第5期422-426,共5页Chinese Journal of Cardiac Pacing and Electrophysiology

基  金:国家自然科学基金资助项目(项目编号:30772886)

摘  要:目的研究夹竹桃麻素(APO)对过氧化氢(H2O2)引起的兔单个心房肌细胞超速激活延迟整流钾电流(IKUr)及瞬时外向钾电流(Ito)异常的保护作用。方法用酶解法分离兔心房肌细胞,将细胞分为4组:对照组(细胞不经任何处理)、H2O2组(细胞经50μmol/L的H2O2培养0.5 h)、H2O2+APO组(细胞预先经100μg/ml APO培养1 h后再加入50μmol/L的H2O2培养0.5 h)、APO组(细胞经100μg/mlAPO培养1.5 h)。采用全细胞膜片钳技术记录4组细胞IKUr和Ito,分析50μmol/L的H2O2对兔单个心房肌细胞IKUr及Ito的影响,并研究预先应用100μg/ml APO对其的保护作用。结果①与对照组比较,H2O2组使兔心房肌细胞IKUr峰值降低(6.1±1.4 pA/pF vs16.0±2.1 pA/pF,P<0.05,n=15),而H2O2+APO组使电流得到部分恢复(10.1±1.3 pA/pF),与H2O2组比差异有显著性(P<0.01,n=15),APO组(15.3±1.2 pA/pF)较对照组变化不大(P>0.05,n=15)。②与对照组比较,H2O2组使兔心房肌细胞Ito峰值降低(20.8±2.0 pA/pF vs 42.6±3.0 pA/pF,P<0.05),而H2O2+APO组使电流得到部分恢复(31.8±2.7 pA/pF),与H2O2组比差异显著(P<0.05,n=15),APO组(40.1±2.9 pA/pF),与对照组相比变化不大(P>0.05,n=15)。H2O2使Ito通道稳态激活曲线右移,通道稳态失活曲线及恢复时间不变,关闭态失活加速,APO可以部分恢复上述改变。结论 APO可减轻氧化应激对心房肌细胞IKUr及Ito的影响。Objective To study the protective effect of apocynin(APO) on abnormalities of ultra rapid delayed rectifier potassium current (IKUr ) and transient outward potassium current ( Ito ) induced by hydrogen peroxide in single rabbit atrial myocytes. Methods Atrial myocytes were enzymatically isolated from rabbits. Myocytes were divided into 4 groups: control group( no treatment) , APO group( cells cultured with 100 μg/ml APO for 1.5 hours ) , H202 group (cells cultured with 50 μmol/L H202 for O. 5 hour) and H2O2 + APO group( cells cultured with 100 μg/ml APO for 1 hour and then cultured with H202 for 0.5 hour). Whole cell patch clamp technique was used to study the effect of H202 (50 txmol/L) on IKUr and Ito in single rabbit atrial myocytes and the effect of pretreatment with apocynin ( 100μg/ml). Results ①H2O2 group reduced the peak current of IKUr from 16.0± 2. 1 pA/pF to 6.1 ± 1.4 pA/pF ( P 〈 0. 05 ), H2O2 + APO group regained the peak to 10. 1 ±1.3 pA/pF(P 〈0.01, n = 15) and APO group had little changes ( 15.3 ±1. 2 pA/pF). ②H2O2 group reduced the peak current of Ito from 39.3 ± 5.4 pA/pF to 32.8±2.0 pA/pF ( P 〈 0. 05 ), H202 + APO group regained the peak to 31.8 ± 2.7 pA/pF ( P 〈 0.01, n = 15 ) and APO group had little changes (40.1 ± 2.9 pA/pF).H2O2 group made the steady-state activation curve of Ito shifted positive potentials, steady-state inactivation and recovery from inactivation of Ito did not change markedly and the closed-state inactivation of I,o was accelerated. In addition, APO protected the changes of Ito dynamics induced by H2O2. Conclusion Apocynin can alleviate the abnormalities of IKUr and It,, induced by hydrogen peroxide in atrial myocytes.

关 键 词:电生理学 夹竹桃麻素 心房肌细胞 过氧化氢 超速激活延迟整流钾电流 瞬时外向钾电流 

分 类 号:R331.38[医药卫生—人体生理学]

 

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