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Collins HE. Female cardiovascular biology and resilience in the setting of physiological and pathological stress. Redox Biol 2023; 63:102747. [PMID: 37216702 PMCID: PMC10209889 DOI: 10.1016/j.redox.2023.102747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 04/29/2023] [Accepted: 05/12/2023] [Indexed: 05/24/2023] Open
Abstract
For years, females were thought of as smaller men with complex hormonal cycles; as a result, females have been largely excluded from preclinical and clinical research. However, in the last ten years, with the increased focus on sex as a biological variable, it has become clear that this is not the case, and in fact, male and female cardiovascular biology and cardiac stress responses differ substantially. Premenopausal women are protected from cardiovascular diseases, such as myocardial infarction and resultant heart failure, having preserved cardiac function, reduced adverse remodeling, and increased survival. Many underlying biological processes that contribute to ventricular remodeling differ between the sexes, such as cellular metabolism; immune cell responses; cardiac fibrosis and extracellular matrix remodeling; cardiomyocyte dysfunction; and endothelial biology; however, it is unclear how these changes afford protection to the female heart. Although many of these changes are dependent on protection provided by female sex hormones, several of these changes occur independent of sex hormones, suggesting that the nature of these changes is more complex than initially thought. This may be why studies focused on the cardiovascular benefits of hormone replacement therapy in post-menopausal women have provided mixed results. Some of the complexity likely stems from the fact that the cellular composition of the heart is sexually dimorphic and that in the setting of MI, different subpopulations of these cell types are apparent. Despite the documented sex-differences in cardiovascular (patho)physiology, the underlying mechanisms that contribute are largely unknown due to inconsistent findings amongst investigators and, in some cases, lack of rigor in reporting and consideration of sex-dependent variables. Therefore, this review aims to describe current understanding of the sex-dependent differences in the myocardium in response to physiological and pathological stressors, with a focus on the sex-dependent differences that contribute to post-infarction remodeling and resultant functional decline.
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Affiliation(s)
- Helen E Collins
- Center for Cardiometabolic Science, Christina Lee Brown Envirome Institute, Division of Environmental Medicine, Department of Medicine, Delia B. Baxter Research Building, University of Louisville, 580 S. Preston S, Louisville, KY 40202, USA.
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2
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Prajapati C, Koivumäki J, Pekkanen-Mattila M, Aalto-Setälä K. Sex differences in heart: from basics to clinics. Eur J Med Res 2022; 27:241. [DOI: 10.1186/s40001-022-00880-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 10/24/2022] [Indexed: 11/11/2022] Open
Abstract
AbstractSex differences exist in the structure and function of human heart. The patterns of ventricular repolarization in normal electrocardiograms (ECG) differ in men and women: men ECG pattern displays higher T-wave amplitude and increased ST angle. Generally, women have longer QT duration because of reduced repolarization reserve, and thus, women are more susceptible for the occurrence of torsades de pointes associated with drugs prolonging ventricular repolarization. Sex differences are also observed in the prevalence, penetrance and symptom severity, and also in the prognosis of cardiovascular disease. Generally, women live longer, have less clinical symptoms of cardiac diseases, and later onset of symptoms than men. Sex hormones also play an important role in regulating ventricular repolarization, suggesting that hormones directly influence various cellular functions and adrenergic regulation. From the clinical perspective, sex-based differences in heart physiology are widely recognized, but in daily practice, cardiac diseases are often underdiagnosed and untreated in the women. The underlying mechanisms of sex differences are, however, poorly understood. Here, we summarize sex-dependent differences in normal cardiac physiology, role of sex hormones, and differences in drug responses. Furthermore, we also discuss the importance of human induced pluripotent stem cell-derived cardiomyocytes in further understanding the mechanism of differences in women and men.
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Discussion on Repolarization Reserve between Patients with Coronary Heart Disease and Normal Controls. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2022; 2022:7944969. [PMID: 36035296 PMCID: PMC9410869 DOI: 10.1155/2022/7944969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 07/20/2022] [Accepted: 07/29/2022] [Indexed: 11/17/2022]
Abstract
Objective To investigate the repolarization reserve of normal controls (NCs) and patients with coronary heart disease (CHD). Methods From January 1st, 2010 to December 31st, 2018, 200 age- and gender-matched inpatients in the Second Hospital of Shanxi Medical University and Heji Hospital Affiliated to Changzhi Medical College were selected for treadmill exercise test (TET), including 67 patients in the myocardial ischemia group, 66 patients in the suspected myocardial ischemia group, and 67 patients in the normal control group. Coronary angiography (CAG) was performed on 49 of 133 patients in the myocardial ischemia group and the suspected myocardial ischemia group, and 9 positives and 40 negatives were identified. The heart rate (HR) and QT interval of TET examiners before exercise, during exercise (90 beats/min, 120 beats/min, maximum HR), and in the recovery period (1 minute and 3 minutes after exercise) were reviewed, and QTc values were calculated after being corrected by BaZett's. Results The mean QTc values in NCs were all below 452 ms, before exercise, during exercise (90 beats/min, 120 beats/min and maximum HR), and during the recovery period (1 minute and 3 minutes after exercise). The comparison results of the RR interval between the two groups revealed P > 0.05, indicating no statistical significance. Significant differences were present when comparing the QT intervals when the HRs were 90 beats/minute and 120 beats/minute during exercise (P < 0.05). And comparing the QTc values, it was found that the QTc values during different exercise periods were statistically different between groups (P < 0.05). Conclusions NCs have good repolarization reserve. CAG can confirm true myocardial ischemia patients (i.e., patients with CHD) among myocardial ischemia and suspected myocardial ischemia patients screened by TET. Patients with positive CAG have poor repolarization reserve as QT interval represents ventricular repolarization adaptability.
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4
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Lock R, Al Asafen H, Fleischer S, Tamargo M, Zhao Y, Radisic M, Vunjak-Novakovic G. A framework for developing sex-specific engineered heart models. NATURE REVIEWS. MATERIALS 2021; 7:295-313. [PMID: 34691764 PMCID: PMC8527305 DOI: 10.1038/s41578-021-00381-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/20/2021] [Indexed: 05/02/2023]
Abstract
The convergence of tissue engineering and patient-specific stem cell biology has enabled the engineering of in vitro tissue models that allow the study of patient-tailored treatment modalities. However, sex-related disparities in health and disease, from systemic hormonal influences to cellular-level differences, are often overlooked in stem cell biology, tissue engineering and preclinical screening. The cardiovascular system, in particular, shows considerable sex-related differences, which need to be considered in cardiac tissue engineering. In this Review, we analyse sex-related properties of the heart muscle in the context of health and disease, and discuss a framework for including sex-based differences in human cardiac tissue engineering. We highlight how sex-based features can be implemented at the cellular and tissue levels, and how sex-specific cardiac models could advance the study of cardiovascular diseases. Finally, we define design criteria for sex-specific cardiac tissue engineering and provide an outlook to future research possibilities beyond the cardiovascular system.
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Affiliation(s)
- Roberta Lock
- Department of Biomedical Engineering, Columbia University, New York, NY USA
| | - Hadel Al Asafen
- Institute of Biomedical Engineering, University of Toronto, Toronto, Ontario Canada
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario Canada
| | - Sharon Fleischer
- Department of Biomedical Engineering, Columbia University, New York, NY USA
| | - Manuel Tamargo
- Department of Biomedical Engineering, Columbia University, New York, NY USA
| | - Yimu Zhao
- Department of Biomedical Engineering, Columbia University, New York, NY USA
| | - Milica Radisic
- Institute of Biomedical Engineering, University of Toronto, Toronto, Ontario Canada
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario Canada
| | - Gordana Vunjak-Novakovic
- Department of Biomedical Engineering, Columbia University, New York, NY USA
- Department of Medicine, Columbia University, New York, NY USA
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5
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Costa S, Saguner AM, Gasperetti A, Akdis D, Brunckhorst C, Duru F. The Link Between Sex Hormones and Susceptibility to Cardiac Arrhythmias: From Molecular Basis to Clinical Implications. Front Cardiovasc Med 2021; 8:644279. [PMID: 33681311 PMCID: PMC7925388 DOI: 10.3389/fcvm.2021.644279] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Accepted: 01/27/2021] [Indexed: 12/30/2022] Open
Abstract
It is well-known that gender is an independent risk factor for some types of cardiac arrhythmias. For example, males have a greater prevalence of atrial fibrillation and the Brugada Syndrome. In contrast, females are at increased risk for the Long QT Syndrome. However, the underlying mechanisms of these gender differences have not been fully identified. Recently, there has been accumulating evidence indicating that sex hormones may have a significant impact on the cardiac rhythm. In this review, we describe in-depth the molecular interactions between sex hormones and the cardiac ion channels, as well as the clinical implications of these interactions on the cardiac conduction system, in order to understand the link between these hormones and the susceptibility to arrhythmias.
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Affiliation(s)
- Sarah Costa
- Arrhythmia and Electrophysiology, Department of Cardiology, University Heart Center, Zurich, Switzerland
| | - Ardan M Saguner
- Arrhythmia and Electrophysiology, Department of Cardiology, University Heart Center, Zurich, Switzerland
| | - Alessio Gasperetti
- Arrhythmia and Electrophysiology, Department of Cardiology, University Heart Center, Zurich, Switzerland.,Cardiac Arrhythmia Service, Department of Cardiology, Johns Hopkins Hospital, Baltimore, MD, United States
| | - Deniz Akdis
- Arrhythmia and Electrophysiology, Department of Cardiology, University Heart Center, Zurich, Switzerland
| | - Corinna Brunckhorst
- Arrhythmia and Electrophysiology, Department of Cardiology, University Heart Center, Zurich, Switzerland
| | - Firat Duru
- Arrhythmia and Electrophysiology, Department of Cardiology, University Heart Center, Zurich, Switzerland.,Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
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6
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Liu M, Li N, Qu C, Gao Y, Wu L, Hu LG. Amylin deposition activates HIF1α and 6-phosphofructo-2-kinase/fructose-2, 6-biphosphatase 3 (PFKFB3) signaling in failing hearts of non-human primates. Commun Biol 2021; 4:188. [PMID: 33580152 PMCID: PMC7881154 DOI: 10.1038/s42003-021-01676-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 01/05/2021] [Indexed: 02/08/2023] Open
Abstract
Hyperamylinemia induces amylin aggregation and toxicity in the pancreas and contributes to the development of type-2 diabetes (T2D). Cardiac amylin deposition in patients with obesity and T2D was found to accelerate heart dysfunction. Non-human primates (NHPs) have similar genetic, metabolic, and cardiovascular processes as humans. However, the underlying mechanisms of cardiac amylin in NHPs, particularly related to the hypoxia inducible factor (HIF)1α and 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) signaling pathways, are unknown. Here, we demonstrate that in NHPs, amylin deposition in heart failure (HF) contributes to cardiac dysfunction via activation of HIF1α and PFKFB3 signaling. This was confirmed in two in vitro cardiomyocyte models. Furthermore, alterations of intracellular Ca2+, reactive oxygen species, mitochondrial function, and lactate levels were observed in amylin-treated cells. Our study demonstrates a pathological role for amylin in the activation of HIF1α and PFKFB3 signaling in NHPs with HF, establishing amylin as a promising target for heart disease patients.
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Affiliation(s)
- Miao Liu
- Department of Translational Safety and Bioanalytical Sciences, Amgen R&D (Shanghai) Co. Ltd., Shanghai, China
| | - Nan Li
- Department of Translational Safety and Bioanalytical Sciences, Amgen R&D (Shanghai) Co. Ltd., Shanghai, China
| | - Chun Qu
- Department of Translational Safety and Bioanalytical Sciences, Amgen R&D (Shanghai) Co. Ltd., Shanghai, China
| | - Yilin Gao
- Department of Translational Safety and Bioanalytical Sciences, Amgen R&D (Shanghai) Co. Ltd., Shanghai, China
| | - Lijie Wu
- Department of Translational Safety and Bioanalytical Sciences, Amgen R&D (Shanghai) Co. Ltd., Shanghai, China
| | - Liangbiao George Hu
- Department of Translational Safety and Bioanalytical Sciences, Amgen R&D (Shanghai) Co. Ltd., Shanghai, China.
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7
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Kamada R, Yokoshiki H, Mitsuyama H, Watanabe M, Mizukami K, Tenma T, Takahashi M, Takada S, Anzai T. Arrhythmogenic β-adrenergic signaling in cardiac hypertrophy: The role of small-conductance calcium-activated potassium channels via activation of CaMKII. Eur J Pharmacol 2019; 844:110-117. [DOI: 10.1016/j.ejphar.2018.12.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 11/29/2018] [Accepted: 12/06/2018] [Indexed: 10/27/2022]
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8
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Masuda K, Takanari H, Morishima M, Ma F, Wang Y, Takahashi N, Ono K. Testosterone-mediated upregulation of delayed rectifier potassium channel in cardiomyocytes causes abbreviation of QT intervals in rats. J Physiol Sci 2018; 68:759-767. [PMID: 29332211 PMCID: PMC10717990 DOI: 10.1007/s12576-017-0590-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 12/26/2017] [Indexed: 12/01/2022]
Abstract
Men have shorter rate-corrected QT intervals (QTc) than women, especially at the period of adolescence or later. The aim of this study was to elucidate the long-term effects of testosterone on cardiac excitability parameters including electrocardiogram (ECG) and potassium channel current. Testosterone shortened QT intervals in ECG in castrated male rats, not immediately after, but on day 2 or later. Expression of Kv7.1 (KCNQ1) mRNA was significantly upregulated by testosterone in cardiomyocytes of male and female rats. Short-term application of testosterone was without effect on delayed rectifier potassium channel current (IKs), whereas IKs was significantly increased in cardiomyocytes treated with dihydrotestosterone for 24 h, which was mimicked by isoproterenol (24 h). Gene-selective inhibitors of a transcription factor SP1, mithramycin, abolished the effects of testosterone on Kv7.1. Testosterone increases Kv7.1-IKs possibly through a pathway related to a transcription factor SP1, suggesting a genomic effect of testosterone as an active factor for cardiac excitability.
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Affiliation(s)
- Kimiko Masuda
- Department of Cardiology and Clinical Examination, Oita University School of Medicine, Yufu, Oita, 879-5593, Japan
- Department of Pathophysiology, Oita University School of Medicine, 1-1 Idaigaoka, Hasama, Yufu, Oita, 879-5593, Japan
| | - Hiroki Takanari
- Department of Pathophysiology, Oita University School of Medicine, 1-1 Idaigaoka, Hasama, Yufu, Oita, 879-5593, Japan
| | - Masaki Morishima
- Department of Pathophysiology, Oita University School of Medicine, 1-1 Idaigaoka, Hasama, Yufu, Oita, 879-5593, Japan
| | - FangFang Ma
- Department of Pathophysiology, Oita University School of Medicine, 1-1 Idaigaoka, Hasama, Yufu, Oita, 879-5593, Japan
| | - Yan Wang
- Department of Cardiology and Clinical Examination, Oita University School of Medicine, Yufu, Oita, 879-5593, Japan
- Department of Pathophysiology, Oita University School of Medicine, 1-1 Idaigaoka, Hasama, Yufu, Oita, 879-5593, Japan
| | - Naohiko Takahashi
- Department of Cardiology and Clinical Examination, Oita University School of Medicine, Yufu, Oita, 879-5593, Japan
| | - Katsushige Ono
- Department of Pathophysiology, Oita University School of Medicine, 1-1 Idaigaoka, Hasama, Yufu, Oita, 879-5593, Japan.
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Linde C, Bongiorni MG, Birgersdotter-Green U, Curtis AB, Deisenhofer I, Furokawa T, Gillis AM, Haugaa KH, Lip GYH, Van Gelder I, Malik M, Poole J, Potpara T, Savelieva I, Sarkozy A. Sex differences in cardiac arrhythmia: a consensus document of the European Heart Rhythm Association, endorsed by the Heart Rhythm Society and Asia Pacific Heart Rhythm Society. Europace 2018; 20:1565-1565ao. [PMID: 29961863 DOI: 10.1093/europace/euy067] [Citation(s) in RCA: 143] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Affiliation(s)
- Cecilia Linde
- Heart and Vascular Theme, Karolinska University Hospital, S-17176 Stockholm, Sweden
| | | | | | | | - Isabel Deisenhofer
- Department of Electrophysiology, German Heart Center Munich, Technical University of Munich, Munich, Germany
| | | | - Anne M Gillis
- Department of Cardiac Sciences, University of Calgary, Libin Cardiovascular Institute of Alberta, Alberta, Canada
| | - Kristina H Haugaa
- Department of Cardiology, Center for Cardiological Innovation and Institute for Surgical Research, Oslo University Hospital, Oslo, Norway
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Gregory Y H Lip
- Institute of Cardiovascular Sciences, University of Birmingham, UK
- Thrombosis Research Unit, Aalborg University, Denmark
| | - Isabelle Van Gelder
- Department of Cardiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Marek Malik
- National Heart and Lung Institute, Imperial College, London
| | - Jeannie Poole
- University of Washington Medical center, Seattle, Washington, USA
| | - Tatjana Potpara
- School of Medicine, Belgrade University, Belgrade, Serbia
- Cardiology Clinic, Clinical Centre of Serbia, Belgrade, Serbia
| | - Irina Savelieva
- St. George's, University of London, Cranmer Terrace, London, UK
| | - Andrea Sarkozy
- Heart Rhythm Management Centre, UZ Brussel-VUB, Brussels, Belgium
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10
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Chen M, Yin D, Guo S, Xu DZ, Wang Z, Chen Z, Rubart-von der Lohe M, Lin SF, Everett Iv TH, Weiss JN, Chen PS. Sex-specific activation of SK current by isoproterenol facilitates action potential triangulation and arrhythmogenesis in rabbit ventricles. J Physiol 2018; 596:4299-4322. [PMID: 29917243 DOI: 10.1113/jp275681] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 06/11/2018] [Indexed: 01/09/2023] Open
Abstract
KEY POINTS It is unknown if a sex difference exists in cardiac apamin-sensitive small conductance Ca2+ -activated K+ (SK) current (IKAS ). There is no sex difference in IKAS in the basal condition. However, there is larger IKAS in female rabbit ventricles than in male during isoproterenol infusion. IKAS activation by isoproterenol leads to action potential triangulation in females, indicating its abundant activation at early phases of repolarization. IKAS activation in females induces negative Ca2+ -voltage coupling and promotes electromechanically discordant phase 2 repolarization alternans. IKAS is important in the mechanisms of ventricular fibrillation in females during sympathetic stimulation. ABSTRACT Sex has a large influence on cardiac electrophysiological properties. Whether sex differences exist in apamin-sensitive small conductance Ca2+ -activated K+ (SK) current (IKAS ) remains unknown. We performed optical mapping, transmembrane potential, patch clamp, western blot and immunostaining in 62 normal rabbit ventricles, including 32 females and 30 males. IKAS blockade by apamin only minimally prolonged action potential (AP) duration (APD) in the basal condition for both sexes, but significantly prolonged APD in the presence of isoproterenol in females. Apamin prolonged APD at the level of 25% repolarization (APD25 ) more prominently than APD at the level of 80% repolarization (APD80 ), consequently reversing isoproterenol-induced AP triangulation in females. In comparison, apamin prolonged APD to a significantly lesser extent in males and failed to restore the AP plateau during isoproterenol infusion. IKAS in males did not respond to the L-type calcium current agonist BayK8644, but was amplified by the casein kinase 2 (CK2) inhibitor 4,5,6,7-tetrabromobenzotriazole. In addition, whole-cell outward IKAS densities in ventricular cardiomyocytes were significantly larger in females than in males. SK channel subtype 2 (SK2) protein expression was higher and the CK2/SK2 ratio was lower in females than in males. IKAS activation in females induced negative intracellular Ca2+ -voltage coupling, promoted electromechanically discordant phase 2 repolarization alternans and facilitated ventricular fibrillation (VF). Apamin eliminated the negative Ca2+ -voltage coupling, attenuated alternans and reduced VF inducibility, phase singularities and dominant frequencies in females, but not in males. We conclude that β-adrenergic stimulation activates ventricular IKAS in females to a much greater extent than in males. IKAS activation plays an important role in ventricular arrhythmogenesis in females during sympathetic stimulation.
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Affiliation(s)
- Mu Chen
- Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA.,Department of Cardiology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Dechun Yin
- Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA.,Department of Cardiology, First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Shuai Guo
- Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA.,Department of Cardiology, First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Dong-Zhu Xu
- Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA.,Cardiovascular Division, Institute of Clinical Medicine, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Zhuo Wang
- Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA.,Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Zhenhui Chen
- Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Michael Rubart-von der Lohe
- Department of Pediatrics, Riley Heart Research Center, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Shien-Fong Lin
- Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA.,Institute of Biomedical Engineering, National Chiao-Tung University, Hsin-Chu, Taiwan
| | - Thomas H Everett Iv
- Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - James N Weiss
- Departments of Medicine (Cardiology) and Physiology, University of California, Los Angeles, CA, USA
| | - Peng-Sheng Chen
- Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
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11
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Amylin and diabetic cardiomyopathy - amylin-induced sarcolemmal Ca 2+ leak is independent of diabetic remodeling of myocardium. Biochim Biophys Acta Mol Basis Dis 2017; 1864:1923-1930. [PMID: 29066284 DOI: 10.1016/j.bbadis.2017.10.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 10/06/2017] [Accepted: 10/16/2017] [Indexed: 02/08/2023]
Abstract
Amylin is a pancreatic β-cell hormone co-secreted with insulin, plays a role in normal glucose homeostasis, and forms amyloid in the pancreatic islets of individuals with type-2 diabetes. Aggregated amylin is also found in blood and extra-pancreatic tissues, including myocardium. Myocardial amylin accumulation is associated with myocyte Ca2+ dysregulation in diabetic rats expressing human amylin. Whether deposition of amylin in the heart is a consequence of or a contributor to diabetic cardiomyopathy remains unknown. We used amylin knockout (AKO) mice intravenously infused with either human amylin (i.e, the aggregated form) or non-amyloidogenic (i.e., monomeric) rodent amylin to test the hypothesis that aggregated amylin accumulates in the heart in the absence of diabetes. AKO mice infused with human amylin, but not rodent amylin, showed amylin deposits in the myocardium. Cardiac amylin level was larger in males compared to females. Sarcolemmal Ca2+ leak and Ca2+ transients were increased in myocytes isolated from males infused with human amylin while no significant changes occurred in either females injected with human amylin or in rat amylin-infused mice. In isolated cardiac myocytes, the amylin receptor antagonist AC-187 did not effectively block the interaction of amylin with the sarcolemma. In conclusion, circulating aggregated amylin accumulates preferentially in male vs. female hearts and its effects on myocyte Ca2+ cycling do not require diabetic remodeling of the myocardium. This article is part of a Special issue entitled Cardiac adaptations to obesity, diabetes and insulin resistance, edited by Professors Jan F.C. Glatz, Jason R.B. Dyck and Christine Des Rosiers.
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12
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Wang X, Fitts RH. Ventricular action potential adaptation to regular exercise: role of β-adrenergic and KATP channel function. J Appl Physiol (1985) 2017; 123:285-296. [DOI: 10.1152/japplphysiol.00197.2017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 04/21/2017] [Accepted: 05/15/2017] [Indexed: 01/06/2023] Open
Abstract
Regular exercise training is known to affect the action potential duration (APD) and improve heart function, but involvement of β-adrenergic receptor (β-AR) subtypes and/or the ATP-sensitive K+ (KATP) channel is unknown. To address this, female and male Sprague-Dawley rats were randomly assigned to voluntary wheel-running or control groups; they were anesthetized after 6–8 wk of training, and myocytes were isolated. Exercise training significantly increased APD of apex and base myocytes at 1 Hz and decreased APD at 10 Hz. Ca2+ transient durations reflected the changes in APD, while Ca2+ transient amplitudes were unaffected by wheel running. The nonselective β-AR agonist isoproterenol shortened the myocyte APD, an effect reduced by wheel running. The isoproterenol-induced shortening of APD was largely reversed by the selective β1-AR blocker atenolol, but not the β2-AR blocker ICI 118,551, providing evidence that wheel running reduced the sensitivity of the β1-AR. At 10 Hz, the KATP channel inhibitor glibenclamide prolonged the myocyte APD more in exercise-trained than control rats, implicating a role for this channel in the exercise-induced APD shortening at 10 Hz. A novel finding of this work was the dual importance of altered β1-AR responsiveness and KATP channel function in the training-induced regulation of APD. Of physiological importance to the beating heart, the reduced response to adrenergic agonists would enhance cardiac contractility at resting rates, where sympathetic drive is low, by prolonging APD and Ca2+ influx; during exercise, an increase in KATP channel activity would shorten APD and, thus, protect the heart against Ca2+ overload or inadequate filling. NEW & NOTEWORTHY Our data demonstrated that regular exercise prolonged the action potential and Ca2+ transient durations in myocytes isolated from apex and base regions at 1-Hz and shortened both at 10-Hz stimulation. Novel findings were that wheel running shifted the β-adrenergic receptor agonist dose-response curve rightward compared with controls by reducing β1-adrenergic receptor responsiveness and that, at the high activation rate, myocytes from trained animals showed higher KATP channel function.
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Affiliation(s)
- Xinrui Wang
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin
| | - Robert H. Fitts
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin
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13
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Hormones and sex differences: changes in cardiac electrophysiology with pregnancy. Clin Sci (Lond) 2017; 130:747-59. [PMID: 27128800 DOI: 10.1042/cs20150710] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 02/01/2016] [Indexed: 11/17/2022]
Abstract
Disruption of cardiac electrical activity resulting in palpitations and syncope is often an early symptom of pregnancy. Pregnancy is a time of dramatic and dynamic physiological and hormonal changes during which numerous demands are placed on the heart. These changes result in electrical remodelling which can be detected as changes in the electrocardiogram (ECG). This gestational remodelling is a very under-researched area. There are no systematic large studies powered to determine changes in the ECG from pre-pregnancy, through gestation, and into the postpartum period. The large variability between patients and the dynamic nature of pregnancy hampers interpretation of smaller studies, but some facts are consistent. Gestational cardiac hypertrophy and a physical shift of the heart contribute to changes in the ECG. There are also electrical changes such as an increased heart rate and lengthening of the QT interval. There is an increased susceptibility to arrhythmias during pregnancy and the postpartum period. Some changes in the ECG are clearly the result of changes in ion channel expression and behaviour, but little is known about the ionic basis for this electrical remodelling. Most information comes from animal models, and implicates changes in the delayed-rectifier channels. However, it is likely that there are additional roles for sodium channels as well as changes in calcium homoeostasis. The changes in the electrical profile of the heart during pregnancy and the postpartum period have clear implications for the safety of pregnant women, but the field remains relatively undeveloped.
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Lin WY, Chou WC, Chang PC, Chou CC, Wen MS, Ho MY, Lee WC, Hsieh MJ, Lin CC, Tsai TH, Lee MY. Identification of Location Specific Feature Points in a Cardiac Cycle Using a Novel Seismocardiogram Spectrum System. IEEE J Biomed Health Inform 2016; 22:442-449. [PMID: 28113792 DOI: 10.1109/jbhi.2016.2620496] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Seismocardiogram (SCG) or mechanocardiography is a noninvasive cardiac diagnostic method; however, previous studies used only a single sensor to detect cardiac mechanical activities that will not be able to identify location-specific feature points in a cardiac cycle corresponding to the four valvular auscultation locations. In this study, a multichannel SCG spectrum measurement system was proposed and examined for cardiac activity monitoring to overcome problems like, position dependency, time delay, and signal attenuation, occurring in traditional single-channel SCG systems. ECG and multichannel SCG signals were simultaneously recorded in 25 healthy subjects. Cardiac echocardiography was conducted at the same time. SCG traces were analyzed and compared with echocardiographic images for feature point identification. Fifteen feature points were identified in the corresponding SCG traces. Among them, six feature points, including left ventricular lateral wall contraction peak velocity, septal wall contraction peak velocity, transaortic peak flow, transpulmonary peak flow, transmitral ventricular relaxation flow, and transmitral atrial contraction flow were identified. These new feature points were not observed in previous studies because the single-channel SCG could not detect the location-specific signals from other locations due to time delay and signal attenuation. As the results, the multichannel SCG spectrum measurement system can record the corresponding cardiac mechanical activities with location-specific SCG signals and six new feature points were identified with the system. This new modality may help clinical diagnoses of valvular heart diseases and heart failure in the future.
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Němec J, Kim JJ, Salama G. The link between abnormal calcium handling and electrical instability in acquired long QT syndrome--Does calcium precipitate arrhythmic storms? PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2015; 120:210-21. [PMID: 26631594 DOI: 10.1016/j.pbiomolbio.2015.11.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 11/17/2015] [Accepted: 11/19/2015] [Indexed: 12/19/2022]
Abstract
Release of Ca(2+) ions from sarcoplasmic reticulum (SR) into myocyte cytoplasm and their binding to troponin C is the final signal form myocardial contraction. Synchronous contraction of ventricular myocytes is necessary for efficient cardiac pumping function. This requires both shuttling of Ca(2+) between SR and cytoplasm in individual myocytes, and organ-level synchronization of this process by means of electrical coupling among ventricular myocytes. Abnormal Ca(2+) release from SR causes arrhythmias in the setting of CPVT (catecholaminergic polymorphic ventricular tachycardia) and digoxin toxicity. Recent optical mapping data indicate that abnormal Ca(2+) handling causes arrhythmias in models of both repolarization impairment and profound bradycardia. The mechanisms involve dynamic spatial heterogeneity of myocardial Ca(2+) handling preceding arrhythmia onset, cell-synchronous systolic secondary Ca(2+) elevation (SSCE), as well as more complex abnormalities of intracellular Ca(2+) handling detected by subcellular optical mapping in Langendorff-perfused hearts. The regional heterogeneities in Ca(2+) handling cause action potential (AP) heterogeneities through sodium-calcium exchange (NCX) activation and eventually overwhelm electrical coupling of the tissue. Divergent Ca(2+) dynamics among different myocardial regions leads to temporal instability of AP duration and - on the patient level - in T wave lability. Although T-wave alternans has been linked to cardiac arrhythmias, non-alternans lability is observed in pre-clinical models of the long QT syndrome (LQTS) and CPVT, and in LQTS patients. Analysis of T wave lability may provide a real-time window on the abnormal Ca(2+) dynamics causing specific arrhythmias such as Torsade de Pointes (TdP).
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Affiliation(s)
- Jan Němec
- Department of Medicine, Heart and Vascular Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Jong J Kim
- Department of Medicine, Heart and Vascular Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Guy Salama
- Department of Medicine, Heart and Vascular Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA.
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Ayaz O, Howlett SE. Testosterone modulates cardiac contraction and calcium homeostasis: cellular and molecular mechanisms. Biol Sex Differ 2015; 6:9. [PMID: 25922656 PMCID: PMC4411792 DOI: 10.1186/s13293-015-0027-9] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 03/27/2015] [Indexed: 02/06/2023] Open
Abstract
The incidence of cardiovascular disease rises dramatically with age in both men and women. Because a woman's risk of cardiovascular disease rises markedly after the onset of menopause, there has been growing interest in the effect of estrogen on the heart and its role in the pathophysiology of these diseases. Much less attention has been paid to the impact of testosterone on the heart, even though the levels of testosterone also decline with age and low-testosterone levels are linked to the development of cardiovascular diseases. The knowledge that receptors for all major sex steroid hormones, including testosterone, are present on individual cardiomyocytes suggests that these hormones may influence the heart at the cellular level. Indeed, it is well established that there are male-female differences in intracellular Ca(2+) release and contraction in isolated ventricular myocytes. Growing evidence suggests that these differences arise from effects of sex steroid hormones on processes involved in intracellular Ca(2+) homeostasis. This review considers how myocardial contractile function is modified by testosterone, with a focus on the impact of testosterone on processes that regulate Ca(2+) handling at the level of the ventricular myocyte. The idea that testosterone regulates Ca(2+) handling in the heart is important, as Ca(2+) dysregulation plays a key role in the pathogenesis of a variety of different cardiovascular diseases. A better understanding of sex hormone regulation of myocardial Ca(2+) homeostasis may reveal new targets for the treatment of cardiovascular diseases in all older adults.
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Affiliation(s)
- Omar Ayaz
- Department of Pharmacology, Dalhousie University, 5850 College Street, Sir Charles Tupper Medical Building, PO Box 15000, Halifax, NS B3H 4R2 Canada
| | - Susan Ellen Howlett
- Department of Pharmacology, Dalhousie University, 5850 College Street, Sir Charles Tupper Medical Building, PO Box 15000, Halifax, NS B3H 4R2 Canada
- Medicine (Geriatric Medicine), Dalhousie University, 5850 College Street, PO Box 15000, Halifax, NS B3H 4R2 Canada
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Hoeker GS, Hood AR, Katra RP, Poelzing S, Pogwizd SM. Sex differences in β-adrenergic responsiveness of action potentials and intracellular calcium handling in isolated rabbit hearts. PLoS One 2014; 9:e111411. [PMID: 25340795 PMCID: PMC4207827 DOI: 10.1371/journal.pone.0111411] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 10/02/2014] [Indexed: 11/20/2022] Open
Abstract
Cardioprotection in females, as observed in the setting of heart failure, has been attributed to sex differences in intracellular calcium handling and its modulation by β-adrenergic signaling. However, further studies examining sex differences in β-adrenergic responsiveness have yielded inconsistent results and have mostly been limited to studies of contractility, ion channel function, or calcium handling alone. Given the close interaction of the action potential (AP) and intracellular calcium transient (CaT) through the process of excitation-contraction coupling, the need for studies exploring the relationship between agonist-induced AP and calcium handling changes in female and male hearts is evident. Thus, the aim of this study was to use optical mapping to examine sex differences in ventricular APs and CaTs measured simultaneously from Langendorff-perfused hearts isolated from naïve adult rabbits during β-adrenergic stimulation. The non-selective β-agonist isoproterenol (Iso) decreased AP duration (APD90), CaT duration (CaD80), and the decay constant of the CaT (τ) in a dose-dependent manner (1–316.2 nM), with a plateau at doses ≥31.6 nM. The Iso-induced changes in APD90 and τ (but not CaD80) were significantly smaller in female than male hearts. These sex differences were more significant at faster (5.5 Hz) than resting rates (3 Hz). Treatment with Iso led to the development of spontaneous calcium release (SCR) with a dose threshold of 31.6 nM. While SCR occurrence was similar in female (49%) and male (53%) hearts, the associated ectopic beats had a lower frequency of occurrence (16% versus 40%) and higher threshold (100 nM versus 31.6 nM) in female than male hearts (p<0.05). In conclusion, female hearts had a decreased capacity to respond to β-adrenergic stimulation, particularly under conditions of increased demand (i.e. faster pacing rates and “maximal” levels of Iso effects), however this reduced β-adrenergic responsiveness of female hearts was associated with reduced arrhythmic activity.
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Affiliation(s)
- Gregory S. Hoeker
- Departments of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Ashleigh R. Hood
- Departments of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Rodolphe P. Katra
- Departments of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Steven Poelzing
- Department of Biomedical Engineering, Virginia Tech Carilion Research Institute, Roanoke, Virginia, United States of America
| | - Steven M. Pogwizd
- Departments of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- * E-mail:
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18
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Abstract
Sexual dimorphism is a well-established phenomenon, but its degree varies tremendously among species. Since the early days of Einthoven's development of the three-lead galvanometer ECG, we have known there are marked differences in QT intervals of men and women. It required over a century to appreciate the profound implications of sex-based electrophysiological differences in QT interval on the panoply of sex differences with respect to arrhythmia risk, drug sensitivity, and treatment modalities. Little is known about the fundamental mechanism responsible for sex differences in electrical substrate of the human heart, in large part due to the lack of tissue availability. Animal models are an important research tool, but species differences in the sexual dimorphism of the QT interval, the ionic currents underlying the cardiac repolarization, and effects of sex steroids make it difficult to interpolate animal to human sex differences. In addition, in some species, different strains of the same animal model yield conflicting data. Each model has its strengths, such as ease of genetic manipulation in mice or size in dogs. However, many animals do not reproduce the sexual dimorphism of QT seen in humans. To match sex linked prolongation of QT interval and arrhythmogenic phenotype, the current data suggest that the rabbit may be best suited to provide insight into sex differences in humans. In the future, emerging technologies such as induced pluripotent stem cell derived cardiac myocyte systems may offer the opportunity to study sex differences in a controlled hormonal situation in the context of a sex specific human model system.
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Affiliation(s)
- Guy Salama
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania; University of Pittsburgh Medical Center Heart and Vascular Institute, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Glenna C L Bett
- Center for Cellular and Systems Electrophysiology, University at Buffalo, State University of New York, Buffalo, New York; Department of Obstetrics and Gynecology, University at Buffalo, State University of New York, Buffalo, New York; and Department of Physiology and Biophysics, University at Buffalo, State University of New York, Buffalo, New York
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Ruzsnavszky F, Hegyi B, Kistamás K, Váczi K, Horváth B, Szentandrássy N, Bányász T, Nánási PP, Magyar J. Asynchronous activation of calcium and potassium currents by isoproterenol in canine ventricular myocytes. Naunyn Schmiedebergs Arch Pharmacol 2014; 387:457-67. [PMID: 24566722 DOI: 10.1007/s00210-014-0964-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 02/13/2014] [Indexed: 11/25/2022]
Abstract
Adrenergic activation of L-type Ca(2+) and various K(+) currents is a crucial mechanism of cardiac adaptation; however, it may carry a substantial proarrhythmic risk as well. The aim of the present work was to study the timing of activation of Ca(2+) and K(+) currents in isolated canine ventricular cells in response to exposure to isoproterenol (ISO). Whole cell configuration of the patch-clamp technique in either conventional voltage clamp or action potential voltage clamp modes were used to monitor I(Ca), I(Ks), and I(Kr), while action potentials were recorded using sharp microelectrodes. ISO (10 nM) elevated the plateau potential and shortened action potential duration (APD) in subepicardial and mid-myocardial cells, which effects were associated with multifold enhancement of I(Ca) and I(Ks) and moderate stimulation of I(Kr). The ISO-induced plateau shift and I(Ca) increase developed faster than the shortening of APD and stimulation of I(Ks) and I(Kr). Blockade of β1-adrenoceptors (using 300 nM CGP-20712A) converted the ISO-induced shortening of APD to lengthening, decreased its latency, and reduced the plateau shift. In contrast, blockade of β2-adrenoceptors (by 50 nM ICI 118,551) augmented the APD-shortening effect and increased the latency of plateau shift without altering its magnitude. All effects of ISO were prevented by simultaneous blockade of both receptor types. Inhibition of phosphodiesterases decreased the differences observed in the turn on of the ISO-induced plateau shift and APD shortening. ISO-induced activation of I(Ca) is turned on faster than the stimulation of I(Ks) and I(Kr) in canine ventricular cells due to the involvement of different adrenergic pathways and compartmentalization.
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Affiliation(s)
- Ferenc Ruzsnavszky
- Department of Physiology, Medical and Health Science Center, University of Debrecen, Debrecen, Nagyerdei krt 98, 4012, Hungary
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