title: [Toxic effects of ammonium perchlorate on thyroid of rats].
abstract: OBJECTIVE
  To study the effects of toxicity of ammonium perchlorate (AP) on thyroid of rats.
  
  
  METHODS
  Eighty-eight Wistar rats were treated orally with different dosages of AP. Three treated groups received 129, 257, 514 mg.kg(-1).d(-1) of AP respectively and one control group drunk water for 13 weeks. Another 3 groups received 1.2, 46.5, 465.0 mg.kg(-1).d(-1) of AP respectively and one control group drunk water for 36 weeks. The behavior and change of body weight in rats were observed. The levels of thyroid hormones in serum were measured and the pathological changes of thyroid tissue were observed as well.
  
  
  RESULTS
  There were no differences in behavior and change of body weight between different AP exposure time. When the rats were treated with AP 514 mg for 13 weeks, free triiodothyronine (FT3, 2.48 pmol/L), free thyroxin (FT4, 13.33 pmol/L) were lower than those in control group (3.24, 20.92 pmol/L respectively, P<0.05). Thyroid-stimulating hormone (TSH, 0.375 mIU/L), thyroglobulin (TG, 3.37 microg/L) were higher than those in control group (0.29 mIU/L, 2.00 microg/L respectively, P<0.05). When the rats were treated with AP 465 mg for 36 weeks, FT3 (2.65 pmol/L) was lower than that in control group (4.97 pmol/L, P<0.01). FT4 in 46.5, 465 mg groups (10.63, 2.17 pmol/L respectively) were lower than that in control group (15.74 pmol/L, P<0.05, P<0.01). TSH in 465 mg group (0.34 mIU/L) was higher than that in control group (0.14 mIU/L, P<0.05). Histopathologic examination showed that follicle proliferation, no colloid in follicle, gore, follicular diminishing or atresia were found in 46.5, 465 mg groups with a dose-effect relationship.
  
  
  CONCLUSIONS
  The toxic effects of AP on the growth of rats were not found, but those on the thyroid of rats were found significantly. Thyroid is the target organ of AP. It is considered that none effect dose of AP for rat thyroid may be 1.2 mg.kg(-1).d(-1), its threshold dose may be 46.5 mg.kg(-1).d(-1).
authors.affiliation: Institute of Industrial Toxicology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Kai-liang
authors.initials: KL
authors.lastname: Peng
authors.forename: Yun
authors.initials: Y
authors.lastname: Jiang
authors.forename: Su-li
authors.initials: SL
authors.lastname: Zhao
authors.forename: Yan-rong
authors.initials: YR
authors.lastname: Zhang
authors.forename: Cui-rong
authors.initials: CR
authors.lastname: Lu
authors.forename: De-hui
authors.initials: DH
authors.lastname: Peng
authors.forename: Wei-dong
authors.initials: WD
authors.lastname: Liu
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D008297:Male; D010472:Perchlorates / Q000633:toxicity*; D000644:Quaternary Ammonium Compounds / Q000633:toxicity*; D051381:Rats; D017208:Rats, Wistar; D013961:Thyroid Gland / Q000187:drug effects* / Q000473:pathology; D013963:Thyroid Hormones / Q000097:blood; D013972:Thyrotropin / Q000097:blood
chemical_list: D010472:Perchlorates; D000644:Quaternary Ammonium Compounds; D013963:Thyroid Hormones; D013972:Thyrotropin; C053506:ammonium perchlorate