Effects of Electrical Stimulation on Growth and Metabolism of Cardiomyocytes In Vitro

In vivo, cardiomyocytes are stimulated by electricity continuously. So electrical stimulation is an indispensable factor for cardiomyocytes cultured in vitro. In this study, the experimental group neonatal cardiomyocytes received electrical stimulation at different intensities and different frequencies by a electrical stimulation device in vitro. After stimulation, The morphology and beating of cardiomyocytes were observed, and lactate dehydrogenase released in the culture medium, positive ratio of propidium iodide staining, and ATPase activity of the cardiomyocytes were measured. When the electrical stimulation at low intensity and low frequency, the morphology and beating, lactate dehydrogenase released, positive ratio of propidium iodide staining, ATPase activity were all almost unchangeable. However, at higher intensity (10 V/cm) or higher frequency (3.5 Hz), cardiomyocytes stopped beating, lactate dehydrogenase leaking, positive ratio of propidium iodide staining were increased, and ATPase activity was reduced. In conclusion, electrical stimulation at high intensity or frequency damnified neonatal cardiomyocytes in vitro, the proper parameter of electrical stimulation favourable for cardiomyocytes metabolism in vitro was less than 10 V/cm (intensity) and 3.5 Hz (frequency).