过氯酸铵对雄性大鼠甲状腺功能及睾丸的影响

目的 研究过氯酸铵(ammonium perchlorate,AP)对雄性大鼠甲状腺激素及睾丸的影响.方法 雄性SD大鼠20只,随机分为对照组、AP低、中、高剂量组,染毒剂量分别为0、130、260、520mg·kg-1·d-1,以大鼠限量饮水方式连续染毒80 d.检测大鼠血清中甲状腺激素、血清睾酮(T)水平、精子活力,并观察睾丸组织的病理变化.结果 AP染毒3周至80 d,中、高剂量组大鼠体重增长明显低于对照组,差异有统计学意义(P＜0.05,P＜0.01),各组大鼠甲状腺湿重及甲状腺脏器系数均高于对照组,差异有统计学意义(P＜0.05,P＜0.01).高剂量组大鼠睾丸脏器系数明显高于对照组,差异有统计学意义(P＜0.01).各剂量组游离甲状腺素(FT4)水平随染毒剂量的增加均明显降低,与对照组比较,差异有统计学意义(P＜0.05),而游离三碘甲状腺原氨酸(FT3)水平无明显变化.中、高剂量组促甲状腺激素(TSH)均明显低于对照组,差异有统计学意义(P＜0.01).中、高剂量组A、B级精子百分比A∶(12.3%±2.52%)、(14.8%±5.93%),B∶(17.7%±4.63%)、(15.8%±2.28%)]明显低于对照组(27.8%±8.70%),差异有统计学意义(P＜0.01),而D级精子百分比随染毒剂量的增加而逐渐增加,中、高剂量组D级精子百分比(38.0%±3.61%),(40.0%±8.99%)]明显高于对照组(17.0%±5.00%),差异有统计学意义(P＜0.01).各组大鼠血清中血清T水平没有明显改变.结论 AP可对大鼠甲状腺激素水平产生影响,能引起FT4下降;对雄性生殖系统的毒作用主要是使精子活力发生减退性改变.

The effects of ammonium perchlorate on thyroid function and testis in male rats

Objective To study the effects of ammonium perchlorate (AP) on the levels of thyroid hormone and the testis function of male rats.Methods Twenty male rats were randomly divided into 4 groups:control group, low, middle and high AP group.The rats were exposed orally to 0, 130, 260 and 520 mg AP/kg a day for 80 days.The levels of thyroid hormone, testosterone in serum and sperm motility were measured and the testis histological change was observed as well.Results The increase of body weight in high AP group was significantly lower than that in the control group (P＜0.01).The organ coefficients of testis and thyroid in high AP group obviously enhanced, as compared with the control group (P＜0.01).The free thyroxin (FT4) levels of serum in all AP treated groups were significantly lower than that of the control group (P＜0.05).There were no differences of serum FT3 levels between all AP groups and control group, while serum TSH levels in middle and high AP groups decreased significantly, as compared with control group (P＜0.01).In terms of sperm motility, the percentage of Grade A and B sperm in middle and high groups were 12.3%±2.52% and 14.8%±5.93%, 17.7%±4.63%, 15.8%±2.28% respectively, which were significantly lower than that (27.8%±8.70%) in control group (P＜0.01 ).The percentage of Grade D sperm in middle and high groups were 38.0%±3.61% and 40.0%±8.99%, respectively, which were significantly higher than that (17.0%±5.00%) in control group (P＜0.01).No difference of serum testosterone level between all AP groups and control group was observed.Conclusion AP can influence the levels of thyroid hormone and reduce the serum FT4 levels in rats.The main toxic effects on male reproductive system may decrease the sperm motility.