[Effect of extremely low frequency magnetic fields on intracellular free calcium in HepG2 cells]

To study the effect of extremely low frequency magnetic fields on intracellular calcium concentration ([Ca(2+)]i).

Fura-2 loaded HepG2 cells were exposed to 1.55 mT (average value), 16 Hz pulsed magnetic fields for 60 min and to 300 mT, 2 Hz rotating magnetic fields for 5 min, and then [Ca(2+)]i was measured by fluorescence spectrophotometer. [Ca(2+)]i of HepG2 cells was also measured when they were exposed to 0.9 mT [root mean square (rms)], 16 Hz sinusoidal magnetic fields in real time.

The R values (F(340) nm/F(380) nm) of the control and the exposed group were 2.4519 +/- 0.2378 and 2.5266 +/- 0.2915 respectively after HepG2 cells were exposed to 1.55 mT, 16 Hz magnetic fields, 1.365 0 +/- 0.0626 and 1.3602 +/- 0.0771 respectively to 300 mT, 2 Hz rotating magnetic fields. The ratios of the trendline slope [r((501 - 1,000)) / r((0 - 500))] from the data of R values were 1.1213 +/- 0.4559 and 1.0727 +/- 0.1971 respectively (P > 0.05), and the ratios of the intercept [b((501 - 1,000)) / b((0 - 500))] from the trendline were 0.9912 +/- 0.0098 and 0.9979 +/- 0.0060 (P > 0.05) when HepG2 cells were exposed to the 0.9 mT, 16 Hz sinusoidal magnetic fields.

The effect of extremely low frequency magnetic fields on [Ca(2+)]i of HepG2 cells under the experimental condition has not been found.