摄入不同剂量碘对雄性大鼠生殖系统的影响

The effect of excessive iodine intake on male rat reproductive system

目的研究碘过量对雄性大鼠生殖功能的潜在影响。方法离乳雄性大鼠喂饲添加高碘0.5、1、2.5、5倍饲料为实验组,以喂饲正常饲料(碘含量200μg/kg)为对照组,连续130～136 d,观察生殖器官组织和精子质量的变化。结果实验组动物睾丸重量降低且具有剂量效应关系,高碘1倍以上3组降低明显(P<0.05～0.01);精子活动性指标未见明显影响(P>0.05);精子浓度和总数均呈下降趋势,分别降低6.59%、22.53%、17.36%、18.06%,但仅在高碘1倍组降低明显(P<0.05);高碘各组正常精子形态明显降低(P<0.05);高碘5倍组睾丸组织细胞形态可见轻度改变。结论碘过量对大鼠可能具有潜在的雄性生殖毒害作用。

Objective： To investigate the effect of excessive iodine intake on reproductive organs of male weanling rats. Methods： One hundred and three male weanling rats were fed with feedstuff containing 0, 0. 5, 1, 2.5, and 5-fold higher dosage of iodine in standard iodine-additive salt, i. e. 200, 300, 400, 700 and 1,200 μg/kg, respectively, for 130-136 days. The number of rats for different dosages of iodine was 20, 21, 21, 21 and 20, respectively. The rats fed 200 μg/kg of iodine were taken as the control. For all groups, their structural changes of reproductive organs and sperm quality were evaluated. Results： The three experiment groups fed with 1, 2.5, and 5-fold higher iodine showed an apparent reduction in testicular weight （P〈0. 05-0. 01） by 10.76%, 14.58% and 25.35%, respectively, compared with the control. But significant reduction in testis/body weight ratio was only observed in the 5-fold higher dosage group. The sperm concentration and total sperm count declined in four experiment groups fed with 0.5-5 fold higher dosage of iodine. The sperm concentration was reduced by 6.59%, 22.53%, 17.35% and 18.06%, respectively. The percentage of sperm with normal and abnormal form significantly changed （P〈0.05）. The addition of different doses of iodine showed no apparent adverse effects on other reproductive organs or sperm viability. Conclusions： These results indicated that excessive iodine intake might cause potential hazards on reproductive organs of male rats with respect to spermatogenesis.