Lymphocytes were isolated from sheep, cultivated and divided into the following groups: 1) exposure to a 5 µT magnetic field, 2) exposure to a 50 µT magnetic field, 3) exposure to a 100 µT magnetic field and 4) control group. Four independent experimental trials were conducted within each group.
|Chamber||exposure system was placed inside an air jacketed CO2 incubator|
|Setup||exposure system consisted of a square-shaped Helmholtz coil, which was wound over a Teflon frame of dimension 35 x 35 x 20 cm (l x b x h); an uninterrupted power supply (UPS) provided less than 1% output voltage variation ensuring stable magnetic field generation; a step down transformer was used to reduce voltage down to 15 V, reducing the electric field component; the current source (step down transformer, rheostat etc.) was shielded by mild steel sheet enclosures|
|magnetic flux density||5 µT||-||calibration||-||-|
A magnetic flux density dependent enhancement in the cell viability of lymphocytes was observed in exposure groups (groups 1-3) compared to the control group (group 4) with a significant difference between group 3 (100 µT exposure) and the control group. DNA laddering analysis showed a significant decrease in cell death in group 3 compared to the control group and flow cytometric analysis showed a significant decrease in apoptosis in group 2 (50 µT exposure) and group 3 compared to the control group. There was also a statistically significant decrease in the enzyme activity of caspase-9 in group 3 compared to the control group. Comet assay did not show any significant DNA damage in exposed cells but confirmed the decreased cell death in group 3 compared to the control group.
The authors conclude that exposure of sheep primary lymphocytes to a 50 Hz magnetic field could decrease apoptosis, possibly by the suppression of caspase-9 enzyme activity, leading to an enhanced cell viability.