The animals were divided into four groups (n=36 per group): 1.) sham exposure, 2.) exposure for 1 hour, 3.) exposure for 2 hours, and 4.) exposure for 4 hours. They were exposed or sham exposed on five consecutive days and blood samples were taken on the sixth day.
Exposure duration: 1 h/day, 2 h/day or 4 h/day on 5 consecutive days
|magnetic flux density||0.0207 µT||-||measured||-||-|
In the 2 hours-exposure group, the content of total protein in the serum was significantly decreased in comparison to the control group. The levels of beta-globulin (also in 4 hours-group) and gamma-globulin were significantly decreased in the 1 and 2 hours-exposure groups when compared to the sham exposure.
The enzyme activity of the aspartate aminotransferase was significantly increased in the 4 hours-exposure group compared to the sham exposure while the enzyme activities of the gamma-glutamyltransferase and the malate dehydrogenase were significantly decreased.
In exposed guinea pigs, the total lipid and cholesterol levels were significantly decreased (in the 2 and 4 hours-group) as well as the triglyceride levels (in the 4 hours-group) in comparison to sham exposed animals. Additionally, an exposure for 4 hours daily led to a significant increase in the levels of lipoproteins, cortisol, and glucose in the serum.
The authors conclude that the exposure to extremely low frequency magnetic fields, especially for four hours daily, could have led to biochemical changes in the serum of guinea pigs.