Impact of electromagnetic field generated by mobile phone on prooxidant-antioxidant balance in testes of rats

Abstract

At the present stage of development of civilization human population is continuously exposed to different forms of electromagnetic field, especially that of radio frequency, generated by mobile phones. The long-term exposure to electromagnetic fields, can cause disturbances of the prooxidant/antioxidant balance in living organism and induce oxidative stress. In this study the impact of whole-body exposure to electromagnetic field with a frequency of 900MHz generated by mobile phone on prooxidant/antioxidant balance in the testes of male rats was estimated, by means of analysis of the contents of markers of membrane lipid peroxidation and oxidative stress: malone dialdehyde (MDA) and total oxidant capacity (TOC), respectively, the activity of antioxidant enzymes: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione S-transferase (GST), as well as the contents of marker of the activity of non-enzymatic antioxidant system: total antioxidant capacity (TAC), in homogenates of the testes. The experiment was performed on 20 male Wistar rats, in mean age of 10 weeks, divided into 2 equal groups (consisting of 10 animals), subjected to long-term exposure to electromagnetic field or to sham-exposure, respectively. Rats from examined group were exposed for 28 succeeding days to electromagnetic field with frequency of 900MHz generated by mobile phone Nokia 5110, that was turned on every 1/2 hour by 8 hours daily and emitted signal for 15 s. The mean value of power density of the electromagnetic field registered during initializing of connection was 85.3 µW/m2, and during lasting connection was 17.0 µW/m2. Rats from control group were exposed for 28 succeeding days to sham-exposure, during which they stayed in identical as exposed animals environmental conditions, excluding the influence of electromagnetic field. During the exposure the mobile phone was placed under a cage with animals. After the end of a cycle of 28 daily exposures to electromagnetic field or sham-exposures (control rats), animals were starved by 24 hours, then anaesthetized and next both testes were taken. In the homogenates prepared from the obtained testes the contents of MDA, TOC and TAC, as well as the activity of SOD, CAT, GPx, GR and GST were measured. The biochemical analyses were performed by means of routine spectrophotometric and kinetic methods. As a result of a cycle of repeated exposures, in electromagnetic field-exposed group of rats a significant decrease in the contents of MDA, a significant increase in the contents of TOC, as well as a significant increase in the activity of SOD, GR and GST in testicular tissue homogenates were observed, as compared to control sham-exposed rats. No significant differences in the activity of CAT and GPx, as well as in the contents of TAC in testicular tissue homogenates were noticed between both groups of rats. On the basis of the obtained results it was found, that 4-week lasting exposure of rats to electromagnetic field with physical parameters generated by mobile phone working in a frequency range of 900 MHz, causes in testes a significant increase of oxidative stress without significant changes of lipid peroxidation process intensity, as well as a stimulation of the activity of some antioxidant enzymes without changes in the activity of non-enzymatic antioxidant system.