Effects of Mechanical Stretch on Growth and Metabolism of Cardiomyocytes In Vitro

Mechanical stimulations are critical factors in regulation activities of cardiomyocytes in vivo and in vitro. Cyclic mechanical stretch is an indispensable factor for cardiomyocytes cultured in vitro and construction of engineered cardiac tissue. Optimized parameter of cyclic stretch is key factor for cardiomyocytes culture in vitro. In this study, neonatal cardiomyocytes were subjected to cyclic stretch by a loading device in vitro. Cardiomyocytes received cyclic stretch at different strain magnitudes and different frequencies or cultured normally. After the treatment of stretching, glucose consumption ratio, lactic acid production ratio and ATPase activity of the cardiomyocytes were measured. Intracellular polymeric beta-tubulin expression was analyzed by Western Blot. When the strain magnitude of stretch was 8% and the frequency was 1 Hz, glucose consumption ratio, lactate production ratio and ATPase activity were all higher than other treatment. Polymeric beta-tubulin content increased prominently. In conclusion, the optimized parameter of cyclic stretch favourable for cardiomyocytes metabolism in vitro was 8% (strain magnitude) and 1 Hz (frequency), polymeric beta-tubulin play a role in cardiomyocytes response to mechanical stretch..