[Effect of static magnetic field on proliferation and cell cycle of osteoblast cell.]

Rat calvarias osteoblasts were cultured and put in the static magnetic field of 0 Gs, 400 Gs, 620 Gs, 830 Gs and 1080 Gs for 24 h, 48 h and 72 h, respectively. MTT method was used for detecting osteoblast proliferation and flow cytometry for detecting cell cycle. When the magnetic exposure time extended to 48 h or 72 h, the corresponding OD value of osteoblast with magnetic treatment of 400 Gs or 620 Gs increased obviously with significant difference as compared with 0 Gs group (P<0.05), but such proliferative effect was not shown in the 1080 Gs group (P>0.05). After magnetic exposure with intensity of 620 Gs, G0/G1 phase percentage decreased, but S phase and G2/M phase percentage was significantly higher as compared with control. Proliferation index (PI) increased as well and there was significant difference in contrast to control (P<0.05). Within a certain range of magnetic intensity, magnetic field enhances cell growth in a dose-dependent pattern. And static magnetic field can activate static G1 phase into S phase, increase DNA synthesis, and accelerate cell proliferation.