Postradiation Effects of Low Intensity Electromagnetic Radiation with a Frequency of 900 MHz in Rat Liver

Purpose: To study the changes in the activity of the liver and blood serum creatine kinase (KK) and the nucleus-nucleolus apparatus of hepatocytes of rats, subjected to the low-intensity electromagnetic radiation of 900 MHz and 25 µW/cm2 energy flux density, typical for a range of mobile phones. Material and methods: The experiments were carried out on white outbred male rats of 6 months of age, weighing 180–200g. The generator Panoramic X1-42 was used as a source of radiation having a frequency of 900 MHz. The activity of CK in the blood serum and liver extracts respectively was determined spectrophotometrically, based on the accumulation of free creatine. Using the extent of the DNA content in rat hepatocytes relative to the accepted standard, the distribution of hepatocytes in ploidy (measured in percentage poins) was detected; so was determined the ratio of eu- and aneuploid cells. Results: It appears that the two-hour single total exposure of rats causes more substantial changes in the activity levels of rats both liver and serum creatine kinase than the total time-wise comparable fractional exposure; while the enzyme exhibits signs of significant adaptation. A decrease in the average DNA content of the nucleus and nucleolus, as well as the average number of nucleolus per nucleus, along with an increase in the number of nucleolus-free nuclei after a single radiofrequency irradiation act indicates certain inhibition of the transcriptional activity of hepatocytes. At the same time, a post-radiation increase of hypodiploid cells, half of which are nucleolus-free hepatocytes, as well as an increase in the number of triploid cells, accompanied by a decrease in the number of tetraploid hepatocytes and the disappearance of hypertetraploid hepatocytes, indicate the incidence of death of a significant number of hepatocytes. Conclusion: The rat liver CK is sensitive to the action of both single low-intensity electromagnetic radiation with a frequency of 900 MHz and that dispersed through fractional exposure: the biological effect of a single exposure is more pronounced. The dynamics of the post-radiation changes occurring in the hepatocyte population upon their single radiofrequency irradiation indicates certain inhibition of the transcriptional activity of the hepatocytes, as well as the incidence of death of a significant number of hepatocytes.