首页|期刊导航|老年心脏病学杂志（英文版）|Hyperpolarization activated cation current (If) in cardiac myocytes from pulmonary vein sleeves in the canine with atrial fibrillation
老年心脏病学杂志（英文版）2012，Vol.9Issue(4)：366-374,9.DOI:10.3724/SP.J.1263.2012.04161
Hyperpolarization activated cation current (If) in cardiac myocytes from pulmonary vein sleeves in the canine with atrial fibrillation
Hyperpolarization activated cation current (If) in cardiac myocytes from pulmonary vein sleeves in the canine with atrial fibrillation
摘要
Abstract
Objective To investigate the characteristics of ectopic automaticity and cation current (If) of cardiac myocytes from pulmonary vein (RAP) for 10 weeks, which induced the atrial fibrillation model. Disassociation of PVs of canines yielded single cardiac myocytes from a Landengorff column. Action potential, If and hyperpolarisation activated cyclic nucleotide-gated (HCN) currents were measured with the patch-clamp technique. Results Compared with the control group, cardiac myocytes from the RAP canine PVs had spontaneous diastolic depolarization, shorter action potential duration, and larger If densities. In the group of RAP cells, the half maximal activation potential (V1/2)was found to be less negative (-105.5 ± 5.2 mV) compared to control cells (-87.3 ± 4.9 mV). Current densities of If were increased significantly by β-adrenergic receptor stimulation with isoproterenol and caused an acceleration of current activation. In contrast, If currents in the RAP were reduced by carvedilol, a selective beta-adrenergic receptor. Another important finding is that HCN4-based channels may make a significant contribution to If in PVs cells, but not HCN2. Meanwhile, HCN4 current significantly increases in canine PVs cardiac myocytes with RAP. Conclusions The spontaneous action potential and larger If current were observed in the PVs cardiac myocytes using RAP, which may contribute to more ectopic activity events to trigger and maintain atrial fibrillation.关键词
Cation current/ Cardiac myocytes/ Canine/ Atrial fibrillation/ β-receptorKey words
Cation current/ Cardiac myocytes/ Canine/ Atrial fibrillation/ β-receptor引用本文复制引用
Jia-Yue Li,Yang Li,Hong-Juan Wang,Bin Xu,Xue-Ping Wang,Yi-Cheng Fu,Mei-Yan Chen,De-Xian Zhang,Yan Liu,Qiao Xue..Hyperpolarization activated cation current (If) in cardiac myocytes from pulmonary vein sleeves in the canine with atrial fibrillation[J].老年心脏病学杂志（英文版）,2012,9(4):366-374,9.基金项目
This study was supported by the National Natural Science Foundation of China (No:81170177,No:30770901). （No:81170177,No:30770901）
