مطالعه مورفومتري بافت استخواني جنين رت متعاقب تابش امواج با فركانس 27/12 مگاهرتز

Morphometric study of bone formation of rat embryo after irradiation with 27/12 MHz radiation

Application of electromagnetic fields like continuous shortwave diathermy (SWD) has been used in physical therapy departments. In this study, three groups of pregnant Sprague Dawley rats were exposed to an incident power density of 10 w/cm for 210 minutes at 27/12 MHz during derent periods of gestation. First group of pregnant rats (Experiment I) from day 0 through day 6 of gestation, second group of pregnant rats (Experiment 2) from day 7 through day 13 of gestation and third group of pregnant rats (Experiment 3) from day 14 through day 20 of gestation were exposed to SWD. Three maching control groups (Sham) were irradiated for 210 minutes at 0 power density. An additional control group of pregnant rats recieved no treatment. For evaluation of bone formation and skeletal malformations of rat embryos, morphometric study was performed on the tibia of of the embroys. Findings indicated a reduction in the formation of bone tissue and a reduced development of the tibia in the treated embryos. Morphometric study confirmed a significant reduction in total volume of tibia together with changes in its volumetric composition resulting from reduction in bone formation, cartilage formation and cartilage resorption in treated groups specially in Experiment 2. Reduction of observed bone formation appeared to be caused by SWD induced hyperthermia in the treated groups specially in Experiment 2. However, it seems possible to desscribe some effects of specific action (non- thermal effects) of SWD occuring independently of the rise in temperature. In conclusion, continuous shortwave diathermy (SWD) can act as a teratogene in pre- and post-implantation periods to reduce osteogenesis in embryos.