Abstract:Objective To investigate the influence of mechanical stretch at different frequencies on proliferation and aerobic capacity of mice myoblast cells C2C12. Methods C2C12 cells cultured in vivo were exposed to mechanical strain with the magnitude of 15% at the frequency of 1 and 2 Hz, respectively, for 2 hours per day over a period of 4 days by using Flexercell Cell Tension System, while in control group C2C12 cells were cultured statically. The C2C12 cells were observed by inverted phase contrast microscope. CCK-8 Cell Counting Kit was used to estimate the proliferation of cells. After the experiment, the cells were obtained by trypsin digestion. MitoXpress-Xtra system with oxygen sensitive probe was induced to detect the extracellular oxygen consumption level. Results The morphology of C2C12 cells presented a typical long spindle under the microscope following the mechanical stretch stimulation. The cells were arranged in a certain direction, parallel to the direction of tension stimulation and growing in good condition. Compare with the control group, the cell numbers in 1 Hz group and 2 Hz group were significantly increased (P<0.05). At the 3rd and 4th day, number of cells in 1Hz group was significantly increased than that in 2 Hz group. However, the oxygen consumption capacity increased in both 1 Hz group and 2 Hz group, but no significant difference was found between experiment groups (P>0.05). Conclusions Cyclic mechanical stretch stimulation can effectively induce proliferation of C2C12 cells, which is related to the frequency of mechanical stretch, with the frequency of 1 Hz being optimum. But stretch stimulation has no significant impact on the aerobic ability of C2C12 cells.