Study on Dependence of Mechanotransduction Sensitivity on Cytoskeletal Development Using Cultured Cardiomyocytes

As a basic study on the mechanical effects of ultrasound exposure on biological tissues, the relationship between cytoskeleton development and mechanotransduction sensitivity was investigated using cardiomyocytes isolated from neonatal rats. The cardiomyocytes were cultured on a coverslip with and without an actin polymerization inhibitor, latrunculin A. Development of the cytoskeleton was visualized using a confocal microscope, indicating that the inhibitor can control cytoskeleton development. Mechanotransduction sensitivity was evaluated by determining the threshold condition of ultrasound exposure for induction of pulsation disruption. One-shot of puled ultrasound of 1 MHz in center frequency and 1.3 MPa in peak negative pressure was used to induce pulsation disruption, and a series of ultrasound pulses with increasing burst cycles was used in experiments. The results showed that suppression of cytoskeletal development requires a longer duration of ultrasound pulse to induce disruption, indicating the importance to consider cell morphology in studies on mechanotransduction of cells in vivo.