比索洛尔对大动脉水平左向右分流大鼠窦房结HCN2、HCN4通道mRNA表达及固有心率的影响
目的以大动脉水平左向右分流sD大鼠心衰模型为研究对象,观察固有心率、窦房结起搏电流HCN2及HCN4亚型mRNA在心脏重构过程中的变化,以及选择性β1-受体阻滞剂比索洛尔对它们的影响。方法通过腹腔动静脉造瘘术建立慢性大动脉水平左向右分流心力衰竭模型,并以假手术组动物为对照。共同饲养2月后,随机分别给予安慰剂或比索洛尔。4周后再次行超声心动检查;测定血流动力学改变及固有心率;提取RNA进行实时定量RT—PCR测定各组HCN通道各亚型mRNA的表达水平。结果造模后2月,超声心动图显示,手术组大鼠心脏扩大,左室厚度显著增高,射血分数则显著降低(P〈0.01)。比索洛尔干预4周后未能逆转大动脉水平左向...
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Published in | 西安交通大学学报(医学版) Vol. 34; no. 2; pp. 189 - 193 |
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Main Author | |
Format | Journal Article |
Language | Chinese |
Published |
陕西西安710061%西安交通大学医学院第二附属医院心血管内科,陕西西安,710004
2013
西安交通大学医学院第一附属医院心血管内科,环境与疾病相关基因教育部重点实验室、心血管离子通道病研究室,陕西省分子心脏病学重点实验室 |
Subjects | |
Online Access | Get full text |
ISSN | 1671-8259 |
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Summary: | 目的以大动脉水平左向右分流sD大鼠心衰模型为研究对象,观察固有心率、窦房结起搏电流HCN2及HCN4亚型mRNA在心脏重构过程中的变化,以及选择性β1-受体阻滞剂比索洛尔对它们的影响。方法通过腹腔动静脉造瘘术建立慢性大动脉水平左向右分流心力衰竭模型,并以假手术组动物为对照。共同饲养2月后,随机分别给予安慰剂或比索洛尔。4周后再次行超声心动检查;测定血流动力学改变及固有心率;提取RNA进行实时定量RT—PCR测定各组HCN通道各亚型mRNA的表达水平。结果造模后2月,超声心动图显示,手术组大鼠心脏扩大,左室厚度显著增高,射血分数则显著降低(P〈0.01)。比索洛尔干预4周后未能逆转大动脉水平左向右分流引起的心腔扩大(P〉0.05),但可改善心脏功能(P〈0.05)并提高固有心率(P〈O.01)。HCN通道蛋AmRNA检测显示:①大鼠窦房结组织中HCN2表达占优势,HCN4相对较少(79%、21%);②安慰剂组HCN4mRNA水平较假手术组明显下降(0.09±0.02VS.1.04土0.13,P〈0.01),而HCN2mRNA表达在各组间没有统计学差异;③比索洛尔治疗后,HCN4基因mRNA水平明显回升(O.99±0.15VS.0.09±0.02,P〈0.01)。结论①比索洛尔干预在改善心衰大鼠心脏功能的同时,可以降低基础心率、升高固有心率;②大动脉水平左向右分流导致心衰大鼠窦房结HCN4通道mRNA的表达降低,比索洛尔治疗可以逆转该通道的重构。这是其影响固有心率、改善心功能的可能机制。 |
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Bibliography: | left-to-right shunt; HCN channel; bisoprolol; sinoatrial node; intrinsic heart rate; heart failure Objective To investigate the mRNA expression level of the HCN channel subtypes in sinoatrial node of adult SD rats with volume-overloaded heart failure as well as the effects of bisoprolol on this process and heart rate. Methods Healthy male SD two-month-old rats were selected to establish the abdominal ateriovenous fistula as a left-to-right shunt model in order to induce volume-overload heart failure; sham operated rats served as controls. After the rats were fed together for 2 months, they were randomly administered with placebo or bisoprolol.Echocardiography was performed four weeks later to record intrinsic heart rate and hemodynamic changes. Then the total RNA was extracted and the mRNA expression level of HCN channel subtypes was determined by RT-PCR. Results Two months after the modeling, echocardiography showed that the heart size enlarged, thickness of the left ventricle increased significantly, and eje |
ISSN: | 1671-8259 |