Effect of 935-MHz phone-simulating electromagnetic radiation on endometrial glandular cells during mouse embryo implantation

This study examined the impact of 935MHz phone-simulating electromagnetic radiation on embryo implantation of pregnant mice.Each 7-week-old Kunming (KM) female white mouse was set up with a KM male mouse in a single cage for mating overnight after induction of ovulation.In the first three days of pregnancy,the pregnant mice was exposed to electromagnetic radiation at low-intensity (150 μW/cm2,ranging from 130 to 200 μW/cm2,for 2-or 4-h exposure every day),mid-intensity (570 μW/cm2,ranging from 400 to 700 μW/cm2,for 2-or 4-h exposure every day) or high-intensity (1400 μW/cm2,ranging from 1200 to 1500 μW/cm2,for 2-or 4-h exposure every day),respectively.On the day 4 after gestation (known as the window of murine embryo implantation),the endometrium was collected and the suspension of endometrial glandular cells was made.Laser scanning microscopy was employed to detect the mitochondrial membrane potential and intracellular calcium ion concentration.In high-intensity,2-and 4-h groups,mitochondrial membrane potential of endometrial glandular cells was significantly lower than that in the normal control group (P<0.05).The calcium ion concentration was increased in low-intensity 2-h group but decreased in high-intensity 4-h group as compared with the normal control group (P<0.05).However,no significant difference was found in mitochondrial membrane potential of endometrial glandular cells between low-or mid-intensity groups and the normal control group,indicating stronger intensity of the electromagnetic radiation and longer length of the radiation are required to inflict a remarkable functional and structural damage to mitochondrial membrane.Our data demonstrated that electromagnetic radiation with a 935-MHz phone for 4 h conspicuously decreased mitochondrial membrane potential and lowered the calcium ion concentration of endometrial glandular cells.It is suggested that high-intensity electromagnetic radiation is very likely to induce the death of embryonic cells and decrease the chance of their implantation,thereby posing a high risk to pregnancy.