实用医学杂志 ›› 2023, Vol. 39 ›› Issue (21): 2750-2753.doi: 10.3969/j.issn.1006-5725.2023.21.010

• 基础研究 • 上一篇    下一篇

低温缺血-再灌注对离体大鼠心房肌Kir2.1和CaMKⅡ表达的影响

何幼芹1,高鸿2(),种朋贵1,刘艳秋2,佟睿3,吴学艳3   

  1. 1.贵州中医药大学第二附属医院麻醉科 (贵阳 550003 )
    2.中山大学附属第一医院贵州医院 (贵阳 550025 )
    3.贵州医科大学麻醉学院 (贵阳 550004 )
  • 收稿日期:2023-05-10 出版日期:2023-11-10 发布日期:2023-12-19
  • 通讯作者: 高鸿 E-mail:2169617@qq.com
  • 基金资助:
    贵州省卫生健康委科学技术基金项目(gzwkj2021-270)

Effect of hypothermic ischemia⁃reperfusion on the expression of Kir2.1 and CaMKⅡ in isolated rat atrial myocardium

Youqin HE1,Hong GAO2(),Penggui CHONG1,Yanqiu LIU2,Rui TONG3,Xueyan. WU3   

  1. *.Department of Anesthesiology,the Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine,Guiyang 550003,China
  • Received:2023-05-10 Online:2023-11-10 Published:2023-12-19
  • Contact: Hong GAO E-mail:2169617@qq.com

摘要:

目的 探讨再灌注房性心律失常心房肌复极时程延长的分子机制。 方法 采用随机数字表法将16只由雄性SD大鼠制备的Langendorff离体心脏灌注模型分为对照组(C组,n = 8)和低温缺血-再灌注组(IR组,n = 8)。根据再灌注后是否发生房性心律失常,将IR组进一步细分为再灌注非房性心律失常亚组(N-RAA组)和再灌注房性心律失常亚组(R-AA组)。C组使用37 ℃ K-H液平衡灌注120 min。IR组使用37 ℃ K-H液平衡灌注30 min后停止,注射4 ℃ Thomas液(20 mL/kg)使心脏停跳60 min,停跳30 min时使用半量4 ℃ Thomas液(10 mL/kg)对离体心脏进行复灌[停跳期间用低温Thomas液(4 ℃)对心脏进行保护],后再次灌注37 ℃ K-H液30 min。记录平衡灌注30 min(T0)、平衡灌注105 min/再灌注15 min(T1)和平衡灌注120 min/再灌注30 min(T2)时右心房单相动作电位(MAP),测量单相动作电位复极50%和90%的时程(MAPD50 和MAPD90)。电生理指标监测完后用Western blot检测右心房组织内向整流钾通道2.1(Kir2.1)和Ca2+/CaM依赖激酶Ⅱ(CaMKⅡ)的表达。 结果 与T0时点比较,R-AA组T1、T2时MAPD50、MAPD90明显延长(P < 0.05);与C组比较,R-NAA组和R-AA组T1、T2时MAPD90明显延长(P < 0.05);与R-NAA组比较,R-AA组T1、T2时MAPD50、MAPD90明显延长(P < 0.05)。Western blot 结果显示,R-NAA组和R-AA组Kir2.1表达明显少于C组(P < 0.05),且R-AA组明显少于R-NAA组(P < 0.05);R-NAA组和R-AA组CaMKⅡ表达较C组明显增加(P < 0.05),且R-AA组 CaMKⅡ表达较R-NAA组明显增加(P < 0.05)。 结论 低温缺血-再灌注房性心律失常大鼠心房肌复极时程延长可能与Kir2.1表达下调和CaMKⅡ 表达增加有关。

关键词: 缺血-再灌注, 心房肌, 复极时程, 内向整流钾通道2.1, Ca2+/CaM依赖激酶Ⅱ

Abstract:

Objective To explore the molecular mechanism of prolonged atrial repolarization in rats with reperfusion atrial arrhythmia. Methods Sixteen Langendorff isolated heart perfusion models made by male SD rats were randomly divided into control group (group C,n = 8) and hypothermic ischemia-reperfusion group (group IR,n = 8). According to the occurrence of atrial arrhythmia after reperfusion,group IR was further subdivided into reperfusion non-atrial arrhythmia subgroup (group N-RAA) and reperfusion atrial arrhythmia subgroup (group R-AA ).Group C was perfused with 37 ℃ K-H solution for 120 min. In group IR, the isolated heart was perfused with 37 ℃ K-H solution for 30 min and stopped, and the isolated heart was perfused with 4 ℃ Thomas solution (20 mL/kg) for 60 mins. When the heart stopped for 30 mins, the isolated heart was perfused with a half dose of 4 ℃ Thomas solution (10 ℃). During cardioplegia, the isolated heart was protected by low temperature Thomas solution (4 ℃), and then reperfused for 30 mins with 37 ℃ K-H solution. The monophasic action potential (MAP) of the right atrium was recorded at balanced perfusion for 30 mins (T0),balanced perfusion for 105 mins in group C/reperfusion for 15 mins in group IR(T1) and balanced perfusion for 120 mins in group C/reperfusion for 30 min in group IR(T2); The duration of 50% and 90% repolarization of monophasic action potential (MAPD50 and MAPD90) was measured. After electrophysiological monitoring, the expression of Kir2.1 and CaMKⅡ in right atrium was detected by Western blot. Results Compared with T0, MAPD50 and MAPD90 at T1 and T2 were significantly prolonged in group R-AA (P < 0.05), and MAPD90 at T1 and T2 in group R-NAA and group R-AA were significantly longer than those in group C (P < 0.05).Compared with group R-NAA, MAPD50 and MAPD90 in group R-AA were significantly prolonged at T1 and T2P < 0.05).The results of Western blot showed that the expression of Kir2.1 in group R-NAA and group R-AA was significantly lower than that in group C (P < 0.05), and that in group R-AA was significantly lower than that in group R-NAA (P < 0.05).The expression of CaMKⅡ in group R-NAA and group R-AA was significantly higher than that in group C (P < 0.05), and the expression of CaMKⅡ in group R-AA was significantly higher than that in group R-NAA. Conclusion The prolonged duration of atrial repolarization in rats with hypothermic ischemia-reperfusion atrial arrhythmia may be related to the down-regulation of Kir2.1 expression and the up-regulation of CaMKⅡ expression.

Key words: ischemia-reperfusion, atrial myocardium, duration of repolarization, inwardly rectifying K channels 2.1, Ca2+-calmodulin kinase Ⅱ

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