ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effects of time varied stress on the proliferation of myoblast in rats and provide the basic experimental data for the remodeling of tissue in functional orthopaedics.</p><p><b>METHODS</b>Based on the pulsatile mechanical system founded, this study loaded different strain (2.5, 5.0, 10.0 kPa) to the myoblast of lateral pterygoid muscle. The proliferation of myoblast was detected by 3H-TDR.</p><p><b>RESULTS</b>After 6 hours under time varied strain, the significant proliferation of myoblast (P < 0.05) was observed, and the 5.0 kPa group expressed the best proliferation. After 12 hours under time varied strain, all groups expressed a better proliferation. Meanwhile, the lower frequency (0.40 Hz) had the bigger effect on the proliferation more than in the higher frequency (1.25 Hz) under the same time varied strain.</p><p><b>CONCLUSION</b>The frequency of time varied strain had also the important influence on the proliferation, the lower frequency (0.40 Hz) had the bigger effect on the proliferation more than in the higher frequency (1.25 Hz) under the same time varied strain. In the certain period of time and certain magnitude of time varied strain, the proliferation of myoblasts rised.</p>