To study whether the serum TSH (thyroid stimulating hormone) and T3 (triiodothronine)-T4 (thyroxine) hormone levels of adult male rats could be altered after exposure to 900 MHz GSM-like electromagnetic field generator.
Thyroid activity is regulated by the thyroid stimulating hormone (TSH) (secreted by pituitary). Elevated TSH levels induce the thyroid to elaborate triiodothronine (T3) and thyroxine (T4).
Animals were maintained under a 12 h light/12 h dark cycle and grouped as follows: control group (without stress and electromagnetic field), sham-exposed group and a 900 MHz group.
|Chamber||A special exposure device with five exposure antennas was used. One exposure system consisted of a ventilated round plastic tube cage (12 cm long x 5.5 cm in diameter) and a half-wave dipole antenna.|
|Setup||The whole body of the rat was positioned in close contact above the antenna.|
|Additional info||Rats were allocated to three groups: exposed to EMF, sham-exposed, and control (without stress and EMF).|
TSH values and T3-T4 at the 900MHz exposure group were significantly lower than the sham-exposed group. There were no statistically significant differences in serum TSH values and T3-T4 hormone contents between the control and the sham-exposed group.
These data indicate that 900MHz electromagnetic field emitted by cellular phones decrease serum TSH and T3-T4 levels. This result may be possibly the result of tissue heating. Further investigations are needed in order to clearly show that the degree of TSH and thyroid hormones suppression by radiofrequency electromagnetic field.