Kv1.1 potassium channel subunit deficiency alters ventricular arrhythmia susceptibility, contractility, and repolarization
| العنوان: | Kv1.1 potassium channel subunit deficiency alters ventricular arrhythmia susceptibility, contractility, and repolarization |
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| المؤلفون: | James G. Traylor, Niels Voigt, Edward Glasscock, Dobromir Dobrev, Shenuarin Bhuiyan, Paari Dominic, Krystle Trosclair, Kathryn A. Hamilton, Megan N. Watts, Man Si, Miklós Bitay, István Baczkó, Nicole M. Gautier |
| المصدر: | Physiological Reports |
| بيانات النشر: | Wiley, 2021. |
| سنة النشر: | 2021 |
| مصطلحات موضوعية: | medicine.medical_specialty, Physiology, Heart Ventricles, Medizin, Action Potentials, 030204 cardiovascular system & hematology, arrhythmia, contractility, Sudden death, Intracardiac injection, Contractility, Mice, 03 medical and health sciences, action potential, 0302 clinical medicine, Physiology (medical), Internal medicine, medicine, Animals, Repolarization, Original Research, Mice, Knockout, Kv1.1 Potassium Channel, repolarization, Cardiac electrophysiology, business.industry, Arrhythmias, Cardiac, Myocardial Contraction, Potassium channel, K‐channel, 3. Good health, Disease Models, Animal, Electrophysiology, Cardiology, business, 030217 neurology & neurosurgery |
| الوصف: | Epilepsy‐associated Kv1.1 voltage‐gated potassium channel subunits encoded by the Kcna1 gene have traditionally been considered absent in heart, but recent studies reveal they are expressed in cardiomyocytes where they could regulate intrinsic cardiac electrophysiology. Although Kv1.1 now has a demonstrated functional role in atria, its role in the ventricles has never been investigated. In this work, electrophysiological, histological, and gene expression approaches were used to explore the consequences of Kv1.1 deficiency in the ventricles of Kcna1 knockout (KO) mice at the organ, cellular, and molecular levels to determine whether the absence of Kv1.1 leads to ventricular dysfunction that increases the risk of premature or sudden death. When subjected to intracardiac pacing, KO mice showed normal baseline susceptibility to inducible ventricular arrhythmias (VA) but resistance to VA under conditions of sympathetic challenge with isoproterenol. Echocardiography revealed cardiac contractile dysfunction manifesting as decreased ejection fraction and fractional shortening. In whole‐cell patch‐clamp recordings, KO ventricular cardiomyocytes exhibited action potential prolongation indicative of impaired repolarization. Imaging, histological, and transcript analyses showed no evidence of structural or channel gene expression remodeling, suggesting that the observed deficits are likely electrogenic due to Kv1.1 deficiency. Immunoblots of patient heart samples detected the presence of Kv1.1 at relatively high levels, implying that Kv1.1 contributes to human cardiac electrophysiology. Taken together, this work describes an important functional role for Kv1.1 in ventricles where its absence causes repolarization and contractility deficits but reduced susceptibility to arrhythmia under conditions of sympathetic drive. The functions of Kv1.1 channels in ventricles were explored for the first time revealing that Kv1.1‐deficient mice exhibit resistance to pacing‐induced arrhythmias with isoproterenol, echocardiographic contractility deficits, and underlying action potential prolongation without evidence of structural or channel expression remodeling. Immunoblots of cardiac tissue from patients revealed Kv1.1 protein in human ventricles, suggesting potential involvement in human health and disease. These findings demonstrate new roles for Kv1.1 in the ventricles where it influences arrhythmia susceptibility, contractility, and repolarization. |
| تدمد: | 2051-817X |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::69f6fe475d4eff8a1c64fb373dd26794 https://doi.org/10.14814/phy2.14702 |
| حقوق: | OPEN |
| رقم الأكسشن: | edsair.doi.dedup.....69f6fe475d4eff8a1c64fb373dd26794 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 2051817X |
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