极低频电磁场对小鼠雌性生殖和子代生长发育的影响

Effects of exposure to extremely low frequency electromagnetic fields on reproduction of female mice and development of offsprings

目的研究极低频电磁场(ELF EMFs)暴露对孕鼠妊娠和子代生长发育的影响。方法孕鼠于妊娠期全程暴露于50 Hz、1．2 mT电磁场(8 h/d),观测其体重变化、分娩情况以及仔鼠的生长发育情况。结果ELF EMFs暴露组孕鼠妊娠后期的平均体重增长率为29．0%,明显低于对照组(47．8%),差异有统计学意义(P＜0．01)；分娩率明显降低,仅为对照组的60%,并见有流产、早产及死胎、畸胎情况。ELF EMFs暴露组仔鼠平均每窝胎数为7只,明显低于对照组(11只)；出生2周内平均体重增长率低于对照组,差异均有统计学意义(P＜0．05)；出牙和开眼时间[(252±24)、(336±19)h]迟于对照组[(226±12)、(319±15)h],差异均有统计学意义(P＜0．05)。结论提示妊娠期ELF EMFs暴露可对雌鼠妊娠和子代的生长发育产生不良影响。

Objective To observe the effects of exposure to extremely low frequency electromagnetic fields （ELF EMFs） on pregnant mice and development of offsprings. Methods Female mice were exposed to 50 Hz, 1.2 mT electromagnetic fields during the whole pregnant period（8 h/d）. The body weight of dams, delivery and development of offsprings were observed and measured. Results The increase of body weight of exposed dams （29.0%） was significantly slower than that of the control group （47. 8%） during late pregnancy period （P 〈 0.05）. The producing rate of exposed group was 60% of that of control group. Miscarriage, fetal loss and externally malformed fetus appeared in exposed group. The average number of offsprings of each exposed mouse was significantly decreased（11±1.6 vs 7 ±2.0, P 〈 0.05） and 11 for control group. Regarding the development of offspring,the body weight of prenatally exposed offsprings was increased more slowly than that of the control in the first two weeks after birth（ P 〈 0.05） .Developmental manifestations including eye opening[ （252 ± 24）h] and tooth eruption [ （ 336 ± 19） h ] presented later in exposed offspring [ （226 ±12 ）, （319 ±15 ） h, respectively ] （ P 〈 0.05 ）. eruption Exposure to ELF EMFs during pregnancy period can cause adverse effects on pregnancy of female mice and development of offsprings.