84 rats were divided into 4 groups (n=21 each): 1) control group, 2) administration of melatonin, 3) exposure to microwaves, 4) administration of melatonin and exposure to microwaves. Seven animals of each group were sacrificed and examined after 20, 40 and 60 days of exposure, respectively.
2 mg/kg body weight melatonin was administered intraperitoneally every morning in groups 2 and 4. Animals of the control group received an equal volume of isotonic saline solution.
Modulation type: CW
Exposure duration: continuous for 4h/day for 20, 40 or 60 days
|magnetic flux density||4.86 µT||minimum||measured||-||according to abstract 100 µT (?)|
|magnetic flux density||8.69 µT||maximum||measured||-||according to abstract 300 µT (?)|
|electric field strength||9.88 V/m||minimum||measured||-||according to abstract 54 V/m (?)|
|electric field strength||18.356 V/m||maximum||measured||-||according to abstract 160 V/m (?)|
|SAR||0.089 W/g||mean||estimated||whole body||-|
The lipid peroxidation was significantly increased in group 3 (exposure to microwaves) compared to the control group after 40 and 60 days of exposure. At the same time, it was significantly reduced in group 4 (melatonin + microwaves) compared to group 3.
Moreover, protein oxidation was significantly increased after 20, 40 and 60 days, catalase and xanthine oxidase enzyme activity were significantly increased after 40 and 60 days and the enzyme activity of alkaline deoxyribonuclease I was significantly increased after 60 days of exposure in group 3 compared to the control group and group 2 (melatonin only).
The authors conclude that exposure of rats to a 900 MHz electromagnetic field could cause oxidative stress in the liver and that melatonin might have an antioxidant effect by reducing lipid peroxidation.