Electric fields stimulate DNA synthesis of mouse osteoblast‐like cells (MC3T3‐E1) by a mechanism involving calcium ions

A cell culture system was designed to study the effect of an electric field on bone cells. This system subjected cultured bone cells to a series of high‐voltage pulses at varying amplitudes of electric field without changing the ion concentrations of the culture medium. When mouse osteoblast‐like cells (MC3T3‐E1) were stimulated for 5 min to 20 hr by an electric field (3.19 kV/m, 3 msec, 10 Hz pulses), DNA synthesis was greatly increased. The stimulation occurred only during the growth phase. The electric field also increased incorporation of 45Ca into the cells, but it did not stimulate cAMP production. Adding calcium ionophore A23187 stimulated both 45Ca uptake and DNA synthesis, but dibutyryl cAMP did not stimulate either of them. These results suggest that the electric field stimulates the DNA synthesis of growing osteoblasts by a mechanism involving calcium ions.