Effect of electric currents on DNA synthesis in rat osteosarcoma cells: dependence on conditions that influence cell growth.

Abstract

Effects of sinusoidal 60-Hz electric currents on DNA synthesis in rat osteosarcoma cell (ROS 17/2.8) in culture were investigated using agar electrodes. This exposure system eliminates electrochemical effects at electrode surfaces, minimizes the contribution of magnetic fields and produces no detectable temperature changes (less than +/- 0.1 degrees C) at current densities of up to 1,500 microA r.m.s. (root mean square)/cm2. Thirty-four hours exposure to electric current at intensities of 300-400 microA r.m.s./cm2 enhanced DNA synthesis by 20% relative to controls. The effect depended on serum concentration, cell seeding density, and the age of the cell population at the time of seeding: effects were seen at 0.2% fetal bovine serum, in cells seeded 4 days after previous passage, at 20,000 cells/cm2. These findings indicate that sinusoidal electric currents can midly enhance DNA synthesis in these cells under growth-limiting conditions.