Six pregnant rats were divided into 2 groups (n=3 each): 1) exposure to the electromagnetic field and a 2) non-exposed control group. From each group, 6 pups were randomly selected 21 days after birth and investigated .
|Chamber||plexiglass jar (30 cm x 42 cm x 50 cm)|
|Setup||setup consisted of an oscillator connected to a half-wave dipole antenna (1 mm x 15 cm copper rod) using a coaxial cable; the antenna was installed centrally approximately 11 cm into the open end of the jar; rats were placed within the jar at the same time|
Light microscopy showed cells with large eosinophilic, granular cytoplasm and round and oval nuclei (oncocytic-like cells) in the thymus of exposed animals. In the spleen, cells from the megakaryocyte, erythrocyte and myeloid series were found in exposed animals, suggestive of extramedullary (i.e. outside of the bone marrow) haematopoiesis in the spleen. Thymus and spleen tissue from control group animals did not show pathological changes.
Transmission electron microscopy revealed pathological changes (degeneration of cells and organelles) in thymus and spleen of the exposure group but not in the control group.
In the thymus of exposed animals, lipid peroxidation was significantly increased and the amount of reduced glutathione was significantly reduced compared to the control group. In the spleen of exposed animals, lipid peroxidation and the amount of reduced glutathione were both significantly increased and the superoxide dismutase enzyme activity was significantly reduced compared to the control group.
The authors conclude that prenatal exposure of rats to a 900 MHz electromagnetic field could cause oxidative stress and pathological changes in the spleen and thymus.