慢性间歇性低压低氧对大鼠心室肌细胞瞬时外向和稳态外向钾通道电流的影响  

THE EFFECT OF CHRONIC INTERMITTENT HYPOBARIC HYPOXIA ON TRANSIENT OUTWARD AND STEADY-STATE OUTWARD POTASSIUM CHANNELS CURRENT IN VENTRICULAR MYOCYTES OF RATS

作　　者：李伟聪[1] 杨晶[2] 魏燕[2] 张翼[2] 朱晓光[3] 张黎[3] 

机构地区：[1]解放军总医院心内科&解放军医学院,北京100853 [2]河北医科大学基础医学院生理学教研室,河北石家庄050017 [3]河北医科大学第三医院手外科,河北石家庄050051

出　　处：《河北医科大学学报》2013年第4期373-377,共5页Journal of Hebei Medical University

基　　金：国家自然科学基金资助项目(30572086);国家重点基础研究发展计划项目(2006CB5041006)

摘　　要：目的探讨慢性间歇性低压低氧(chronic intermittent hypobaric hypoxia,CIHH)对大鼠心室肌细胞瞬时外向钾通道电流(transient outward potassium channel current,I_(to))和稳态外向钾通道电流(steady-state outward potassium channel current,I_(ss))的影响。方法通过低压氧舱制备CIHH大鼠模型,全细胞膜片钳方法记录大鼠心室肌细胞I_(to)和I_(ss)。结果基础条件下,28d CIHH处理大鼠心室肌细胞I_(to)电流密度较对照组大鼠心室肌细胞明显增强(P<0.05),而I_(ss)电流密度与对照组大鼠心室肌细胞相比较差异无统计学意义(P>0.05)。模拟缺血可明显降低大鼠心室肌细胞I_(to)和I_(ss)(P<0.05),但CIHH处理大鼠心室肌细胞I_(to)。的降低明显小于对照组大鼠心室肌细胞(P<0.05),而I_(ss)的降低与对照组心室肌细胞差异无统计学意义(P>0.05)。结论 CIHH可增强大鼠心肌细胞I_(to)通道电流,并有效对抗模拟缺血对I_(to)通道的抑制,此作用可能是CIHH抗心律失常作用的离子机制之一。Objective To observe the effect of chronic intermittent hypobaric hypoxia （CIHH） on transient outward potassium channel current （Ito） and steady-state outward potassium channel current （lss） in ventricular myocytes of rats. Methods The rats were treated with CIHH for 28 days in a hypobaric chamber and the whole-cell patch clamp technique was used to record Ito and Iss in ventricular myocytes of rats. Results Compared with the control rats, the current density of Ito in the CIHH rats under basic conditions increased significantly （P 〈 0.05 ）. There was no significant difference in the current density of Iss between the two groups （ P 〉 0.05 ）. The simulated ischemia decreased Ito and Iss obviously in ventricular myocytes of rats （ P 〈 0.05 ）. The decrease of Ito in CIHH rats was significantly less than that in control rats （P 〈 0.05 ）, but there was no difference in Iss between the two groups （P 〉 0. 05）. Conclusion CIHH increased Ito current and effectively antagonized the inhibition of simulated ischemia on Ito channel in ventricular myocytes of rats, which might be one of the ionic mechanisms of anti-arrhythmia of CIHH.

关 键 词：钾通道 肌细胞 心脏 慢性间歇性低压低氧 大鼠 

分 类 号：R331.38[医药卫生—人体生理学]