The ability of bone marrow precursor cells from mice, exposed to a radio frequency field, to colonize thymus and spleen of lethally x-irradiated mice and to differentiate should be investigated. The study is an expansion to the precursor study of Prisco et al., 2008
The study should verify the results of the precursor study and check them with the help of a new, sensitive method. Therefore, two different approaches were conducted: In approach 1, lethally x-irradiated wild type B/6 mice received injections with bone marrow cells from syngenic exposed (1a, n=8), sham exposed (1b, n=8) and cage control animals (1c, n=8). In approach 2, three X-irradiated Rag2 deficient mice received 50:50 mixtures of bone marrow cells: 2a) from cage control (wild type B/6) and sham exposure (congenic B/6)), 2b) from sham exposure (congenic B/6) and exposure (wild type B/6) and 2c) from cage control (congenic B/6) and exposure (wild type B/6).
As Rag2 deficient mice cannot produce mature B cells and T cells, approach 2 was used to detect differences between two different treatments, respectively, with a very high sensitivity, as those cells develop from the transplanted bone marrow cells, compete in the colonization of thymus and spleen and their origin can be tracked. Wild type and congenic donor mice express different variants of the Thy1 surface molecule CD90 on T cells (Thy1a und Thy1b) and of the immunoglobulin heavy chain Igh on B cells (Igha und Ighb), which can be detected with specific antibodies. Investigation took place 12 weeks after transplantation.
|Repetition frequency||217 Hz|
|Chamber||8 mice each were placed in a Transverse ElectroMagnetic (TEM) chamber (12 x 12 x 120 cm) made of transparent cylindrical polymethyl methacrylate|
|Setup||mice were fixed with their caudal axis parallel to the direction of the field propagation and exposed with daily clockwise rotation of the animals|
|Sham exposure||A sham exposure was conducted.|
|SAR||2 W/kg||-||measured and calculated||-||-|
No differences regarding total thymocyte and spleen cell numbers, percentages of subpopulations, cell proliferation and level of interferon-gamma could be found between the groups of test approach 1. Approach 2 revealed a slight but insignificant higher amount of cells stemmed from the cage control animals in mice 2a) and 2c). This was interpreted as a decreased fitness of cells from sham exposure and exposure animals due to the increased stress they had encountered during the exposure procedure.
The authors conclude that their results indicate no effects of a chronic whole body exposure to a 900 MHz GSM electromagnetic field on the ability of bone marrow precursor cells from mice to colonize thymus and spleen and to differentiate and thus that the results of their precursor study are verified.