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Characteristics of Fast Sodium Current in Isolated Quail Cardiomyocytesстатья
- Авторы: Filatova T.S., Abramochkin D.V.
- Журнал: Moscow University Biological Sciences Bulletin
- Том: 77
- Номер: 3
- Год издания: 2022
- Издательство: Allerton Press
- Местоположение издательства: New York, N.Y., United States
- Первая страница: 159
- Последняя страница: 164
- DOI: 10.3103/S0096392522030051
- Аннотация: —Fast sodium current (INa) provides depolarization of the working myocardium, determining theexcitability of its cells and the propagation velocity of excitation. Disturbances of activation and inactivationof sodium channels can lead to the development of various arrhythmias. In most vertebrates, with the exception of mammals, INa has been studied rather poorly, including in birds, which are of great interest for comparative physiology. This work first considers the characteristics of fast sodium current in the myocardium ofadult birds. Using patch clamp method, the authors registered INa in isolated atrial and ventricular cardiomyocytes of Japanese quail. The current had a higher amplitude (in comparison with other vertebrates) andquickly recovered after inactivation; the fast inactivation time constant of INa in atrial myocytes turned out tobe lower than in ventricular cells. The parameters of steady-state activation and inactivation suggest that thesodium window current in the avian myocardium is less pronounced than in the mammalian myocardium.In quail ventricular cardiomyocytes, the late sodium current blocker ranolazine caused a slight decrease inthe peak amplitude of INa and did not affect the inactivation kinetics but shifted the steady-state activationcurve towards more negative potentials, shortened action potentials, and decreased maximum upstrokevelocity. Thus, it can be assumed that these INa characteristics in the quail myocardium reflect the adaptationto the high heart rate in birds and may indicate possible differences in the structure and functioning of sodiumchannels in the hearts of birds and mammals.
- Добавил в систему: Филатова Татьяна Сергеевна