Objective To observe the effects of 17β- estradiol on the intracellular calcium of masticatory muscles myoblast. Methods Myoblasts from maxillofacial skeletal muscle of one week old female Sprague- Dawley rats were cultured. Fluo- 4- AM as the Ca2+ indicator and the laser confocal microscope system were used to observe the effects of estrogen on the cytoplasmic Ca2 + concentration in the normal pH condition and the acid condition （ pH= 6.7）. Results In the normal pH condition, when 17β- estradi（ol 10- 9, 10- 8, 10- 7 mol/L）were added to cells cytoplasmic Ca2+ immediately increased then decreased right away, and in the end came into a new Ca2+ homeostasis in the base line. In the acid condition, 17β- estradio（l 10 - 9, 10 - 8, 10 - 7 mol/L） made the cytoplasmic Ca2 + decreased immediately then came into a new Ca2 + homeostasis under the base line. Conclusion The results suggest that estrogen may maintain the skeletal cytoplasmic Ca2+ concentration in a lower level and reduce the cytoplasmic Ca2+ accumulation to keep the normal functions of masticatory muscles myoblast.
