亚慢性暴露高频电磁场对雌性大鼠性腺的毒性作用

Female genital toxicities of high-frequency electromagnetic field on rats

目的研究亚慢性暴露高频电磁场（HF—EMF，30MHz）对雌性大鼠性腺的毒性作用。方法选用清洁级Wistar雌性大鼠60只，按体重随机分为5组，暴露剂量分别为0、25、100、400、1600V/m，大鼠全身暴露于HF—EMF，8h／d，每周连续5d，停2d，共暴露56d。辐射期间大鼠每3天称1次体重，第48天开始观察大鼠动情周期的变化，56d后待大鼠处于动情期时取血清和卵巢，采用放射免疫法测定相关激素，HE染色法计算卵巢各级卯泡的数目构成比，用电子显微镜观察细胞超微结构。结果各剂量组大鼠体重与卵巢湿重及脏器系数的差异无统计学意义（P〉0．05）；100、400、1600 V／m组大鼠动情前期时间分别为（15．00±5．06）、（11．40±2．05）、（10．56±0．96）h，明显短于对照组[（18．70±2．96）h]，差异有统计学意义（P〈0．01）；400、1600V／m组大鼠动情间期时间分别为（101．20±17．81）、（115．33±19．28）h，明显长于对照组[（69．80±11．42）h]，差异有统计学意义（P〈0．01）。400、1600V／m组的黄体生成素（LH）水平[分别为（11．02±1．11）、（14，70±1．94）mU／ml]明显高于对照组[（8．70±0．53）mU／ml]，差异有统计学意义（P〈0．01）；而雌激素（E2）水平[分别为（57．16±31．56）、（50．57±25．16）pg／ml]明显低于对照组[（95．04±32．62）pg／ml]，差异有统计学意义（P〈0．01）；400、1600V／m组黄体数目构成比（分别为19．75％、19．04％）明湿高于对照组（14．01％），差异有统计学意义（P〈0．01），100、400、1600V／m组闭锁卵泡数目构成比分别为8．45％、9．95％、IL70％，明显高于对照组（7．72％），差异有统计学意义（P〈0．01）；而400、1600V/m组成熟卯泡数目构成比（分别为1．50％、1．55％）明屈低于对照组（3．36％），差异有统计学意义（P〈0．01）；400、1600 V／m组初／次级卵泡数目构成比分别为22．24％、21．09％，明显低于对照组（26．60％），差异有统计学意义（P〈0．01）。随辐射剂量的增大，细胞超微结构改变越明显，细胞核染色质成块，核仁边集，甚至出现核同缩、凋亡小体，线粒体出现肿胀、水肿，甚至呈空泡状。结论HF-EMF（30MHz、100～1600V／m）对雌性性腺有毒性作用，其毒性作用表现在卵巢损害出现较早（如激素分泌功能改变）。

Objective To study on the effects of sub-chronic exposures to high-frequency electromagnetic field （HF-EMF） on the estrous cycle, ovarian pathological changes and related hormones and preliminarily investigate the female genital toxicities of HF-EMF in tats. Methods 60 Wistar female adult rats were randomly divided into five groups based on hody weight and radiated with different levels of 30 MHz electromagnetic field （0, 25, 100, 400 and 1600 V/m） for eight hours daily. Weekly the rats were continuously exposed five days. From the 48th day the four stage of estrus cycle were observed with smear method of the vaginal cell. Fifty-six days later the serum levels of sexual hormones were detected with the radioimmnnoassay on estrus stage. The constituent ratio of the distinct follicle number on ovaries were observed with the HE staining and the uhramicrostructure was ohservcd with the transmission electron microscope. Meanwhile, the ovarial humid weight and organ coefficient were observed. Results There was no significant difference in ovarial humid weight and organ coefficient between the exposure and the control groups. The time of preoestrus in the 100 V/m group, the 400 V/m group and the 1600 V/m group was decreased significantly [（15.00±5.06）,（11.40±2.05 ） and （10.56±0.96） h in the exposure group compared with （18.70±2.96） h in the control group, P〈0.01], and the time of Anestrum in the 400 V/m group and the 1600 V/m group were increased significantly [（ 101.20±17.81 ） and （115.33±19.28） h in the exposure group compared with （69.80±11.42） h in the control group, P〈0.01 ）]. Serum LH in the 400 V/m and 1600 V/m group was increased significantly[（ 11.02±1.11 ） and （14.70±1.94） mU/ml in the exposure groups compared with （8.70±0.53） mU/ml in the control group, P〈0.01], and serum E2 was decreased significantly [（57.16±31.56） and （50.57±25.16） pg/ml in the exposure groups compared with （95.04±32.62） pg/ml in the control group, P〈0.01 ]. The composition ratio of the corpus luteum/ albicans number in the 400 V/m group and the 1600 Vim group was increased significantly （19.75% and 19.04% in the exposure groups compared with 14.01% in the control group, P〈0.05 ）. The composition ratio of the atresic follicle number was increased significantly in the 100 V/m, the 400 V/m and the 1600 Vim group （8.45%, 9.95% and 11.70% in the exposure groups compared with 7.72% in the control group, P〈0.01 ）. The composition ratio of the mature follicle and the pri/sec follicle was decreased significantly in the 400 V/m and the 1600 V/m group （1.50% and 1.55% in the exposure groups compared with 3.36% in the control group. 22.24% and 21.09% in the exposure groups compared with 26.60% in the control group, P〈0.01 ）. Along with the increase of radiation dose, the uhramicrostructure of cell on the ovaries appeared more abnormal. Conclusions The toxicities of female gonads are closely associated with exposures to HF-EMF. The nonage damage of female gonadal toxicities might emerge on the ovaries.