Immature (4 weeks old) and young (10 weeks old) rats were used.
|Exposure duration||repeated daily exposure, 90 min/day, 6 days/week, for 1 or 2 weeks|
|Additional info||Wang J, Fujiwara O. 2004. A new method for realizing local exposure to young rat heads using electric flux concentration for bio-effect test of mobile telephones. Proceedings of the International Symposium on Electromagnetic Compatibility, Sendai, June 2004:581-584.|
|Distance between exposed object and exposure source||3 cm|
|Chamber||The exposure box (90 x 90 x 60 cm) was made of metal, and its walls were inlaid with pyramidal EM wave absorber, except for the metal roof, which formed the ground of the antenna installed vertically in its center [Shirai et al., 2005]. A disk-like plate was supported by a central hollow cylinder pole through which air was ventilated into the box.|
|Setup||Rats were individually fixed in plastic holders and were set on the disk-shaped plate like a carrousel with their noses pointing to the central antenna at a distance of 3 cm. A flexible ferroelectric sheet, 1 mm thick, covering the head part of the plastic holder concentrated the electric flux in a circle which resulted in a strong magnetic field in the region of the rat head.|
|Sham exposure||A sham exposure was conducted.|
|Additional info||Ten exposure boxes were placed in a shielded room, and 10 rats were exposed at the same time with the same SAR. After one week, five rats in each group were sacrificed and replaced by live dummy rats (not used in any analysis) to maintain the exposure condition.|
Although expression of the three genes was decreased after administration of 1,3-dinitrobenzene as a positive control, when compared with the control values, there were no pathologically relevant differences with the electromagnetic field at any exposure levels at either age. Vascular permeability, measured with reference to transfer of FITC-dextran, was not affected by electromagnetic field exposure.
Thus, these data indicate that local exposure of the head to 1439 MHz electromagnetic field exerts no adverse effects on the blood-brain barrier in immature and young rats.