Analysis of DNA fragmentation in mouse embryos exposed to an extremely low-frequency electromagnetic field

Abstract

Effects of extremely low-frequency electromagnetic fields (ELF-EMFs) on DNA damage in biological systems are still a matter of dispute. The aim of the present study was to investigate the possible effect of electromagnetic field exposure on DNA fragmentation in cells (blastomers) of mouse blastocysts. Eighty female NMRI mice were randomly divided into 2 groups of 40 animals each. The control group was left unexposed whereas the animals in the EMF-group were exposed to a 50-Hz EMF at 0.5 mT 4 h per day, 6 days a week for a duration of 2 weeks. After the 8(th) day of exposure, the female mice in both groups were superovulated (with injections of pregnant mare serum gonadotropin and human chorionic gonadotropin) and then mated overnight. At approximately 4 days after mating (102 h after the human chorionic gonadotropin treatment), blastocysts were obtained by flushing the uterus horns. The mean numbers of pregnant mice, blastocysts after flushing, blastomers within the blastocysts, and the DNA fragmentation index following staining in both groups were compared using statistical methods (SPSS, the Chi-square test, the Student's t-test and the Mann-Whitney U-test, P < 0.05). The results showed that the mean number of blastocysts after flushing was significantly decreased in the EMF-group compared to that of the control group (P < 0.03). The DNA fragmentation index was significantly increased in the EMF-group compared to control (10.53% vs. 7.14%; P < 0.001). However, there was no significant difference in the mean numbers of blastomers and numbers of pregnant mice between the EMF-exposed and control group. Our findings indicate that the EMF exposure in preimplantation stage could have detrimental effects on female mouse fertility and embryo development by decreasing the number of blastocysts and increasing the blastocysts DNA fragmentation.

The toxic effects of mobile phone radiofrequency (940 MHz) on the structure of calf thymus DNA

“…It is important to mention that in this study the temperature of the waveguide is controlled via an incubator with 1 1C precision. Our results are consistent with previous research, which indicated that radiofrequency or microwave radiation effect on DNA is non-thermal and causes structural damage to the DNA molecule (Behari, 2010;Borhani et al, 2011;Trosic et al, 2012).…”

A review on Electromagnetic fields (EMFs) and the reproductive system

“…The effects EMFs on implantation and fetal development have been reported. During mating, mice exposed to 50 Hz frequency, 0.5 mT intensity for 4 h/day for two weeks had significant reductions in the number of blastocysts and increases DNA fragmentation (55). This study suggested that exposure to EMFs in the implantation period can have deleterious effects on the development of embryos.…”

Effect of electromagnetic waves on human reproduction

“…The effect of the frequency of 50 Hz on mouse embryos was described by Borhani N. et al [47]. They showed an intensification of DNA fragmentation in blastomers, as well as a decreased percentage of blastocysts among embryos placed in this field.…”