Myocyte repolarization modulates myocardial function in aging dogs
| Autor: | David A. D'Alessandro, Marco Luciani, Thomas H. Hintze, Giulia Borghetti, Ewa Wybieralska, Edward G. Barrett, Khaled Qanud, Maria Cimini, Christopher Royer, Polina Goichberg, Alex Matsuda, Elizabeth Kertowidjojo, Eric Zhang, Yu Zhou, Andrea Sorrentino, Ramaswamy Kannappan, Piero Anversa, Antonio Cannatà, Andrew Webster, Annarosa Leri, Marianna Meo, Oriyanhan Wunimenghe, Marcello Rota, Sergio Signore, Robert E. Michler |
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| Přispěvatelé: | Sorrentino A, Signore S, Qanud K, Borghetti G, Meo M, Cannata A, Zhou Y, Wybieralska E, Luciani M, Kannappan R, Zhang E, Matsuda A, Webster A, Cimini M, Kertowidjojo E, D'Alessandro DA, Wunimenghe O, Michler RE, Royer C, Goichberg P, Leri A, Barrett EG, Anversa P, Hintze TH, Rota M |
| Rok vydání: | 2016 |
| Předmět: |
Male
0301 basic medicine Inotrope Aging medicine.medical_specialty Physiology Population Action Potentials Hemodynamics 030204 cardiovascular system & hematology Biology 03 medical and health sciences Dogs 0302 clinical medicine Ventricular hypertrophy contractile reserve Physiology (medical) Internal medicine myocardium medicine Animals Ventricular Function Myocyte Repolarization Myocytes Cardiac Decompensation Myopathy education education.field_of_study medicine.disease 030104 developmental biology Endocrinology Cardiology Female medicine.symptom Cardiology and Cardiovascular Medicine Muscle Mechanics and Ventricular Function |
| Zdroj: | American Journal of Physiology-Heart and Circulatory Physiology. 310:H873-H890 |
| ISSN: | 1522-1539 0363-6135 |
| Popis: | Studies of myocardial aging are complex and the mechanisms involved in the deterioration of ventricular performance and decreased functional reserve of the old heart remain to be properly defined. We have studied a colony of beagle dogs from 3 to 14 yr of age kept under a highly regulated environment to define the effects of aging on the myocardium. Ventricular, myocardial, and myocyte function, together with anatomical and structural properties of the organ and cardiomyocytes, were evaluated. Ventricular hypertrophy was not observed with aging and the structural composition of the myocardium was modestly affected. Alterations in the myocyte compartment were identified in aged dogs, and these factors negatively interfere with the contractile reserve typical of the young heart. The duration of the action potential is prolonged in old cardiomyocytes contributing to the slower electrical recovery of the myocardium. Also, the remodeled repolarization of cardiomyocytes with aging provides inotropic support to the senescent muscle but compromises its contractile reserve, rendering the old heart ineffective under conditions of high hemodynamic demand. The defects in the electrical and mechanical properties of cardiomyocytes with aging suggest that this cell population is an important determinant of the cardiac senescent phenotype. Collectively, the delayed electrical repolarization of aging cardiomyocytes may be viewed as a critical variable of the aging myopathy and its propensity to evolve into ventricular decompensation under stressful conditions. |
| Databáze: | OpenAIRE |
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