title: [A preliminary study of screening assay for thyroid hormone disruptors in vivo].
abstract: OBJECTIVE
  To study the biological effects of thyroid induced by N',N-methylene-bis (2-amino-5-sulfhydryl-1, 3, 4-thiadianole), discussing whether this agent is a thyroid hormone disruptor.
  
  
  METHODS
  Sixty Wistar rats were divided into 2 groups, including one experiment group and one control. The rats of experiment group were fed with this agent at 50 mg/kg. Whole animals were weighed, then they were sacrificed by bleeding from femoral artery on the fifth, 10th, 20th day, respectively; at the same time, serum T4 and TSH concentrations were examined and the thyroids were taken out and weighed for coefficient of thyroid gland weight; the pathological changes of thyroids were observed under light microscope; the enzyme activity of succinate dehydrogenase and thyroidperoxidase, and the positive expression of PCNA in thyroid gland were examined by histochemistry.
  
  
  RESULTS
  Increased coefficient of thyroid gland weight, proliferation of thyroid epithelium, increased enzyme activity of SDH and TPO, and increased positive cells of PCNA were observed in the experiment group.
  
  
  CONCLUSIONS
  N',N-methylene-bis (2-amino-5-sulfhydryl-1, 3, 4-thiadianole) is likely to be a thyroid hormone disruptor.
authors.affiliation: Department of Toxicology, West China School of Public Health, Sichuan University, Chengdu 610041, China.
authors.forename: Weibo
authors.initials: W
authors.lastname: Cheng
authors.forename: Ding
authors.initials: D
authors.lastname: Sun
authors.forename: Qunying
authors.initials: Q
authors.lastname: Li
authors.forename: Wendong
authors.initials: W
authors.lastname: Wang
authors.forename: Bangliang
authors.initials: B
authors.lastname: Xiao
authors.forename: Desheng
authors.initials: D
authors.lastname: Wu
mesh_terms: D000818:Animals; D005260:Female; D008297:Male; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013830:Thiadiazoles / Q000633:toxicity*; D013961:Thyroid Gland / Q000378:metabolism* / Q000473:pathology; D013963:Thyroid Hormones / Q000097:blood; D013972:Thyrotropin / Q000037:antagonists & inhibitors* / Q000097:blood; D013974:Thyroxine / Q000037:antagonists & inhibitors* / Q000097:blood
chemical_list: D018809:Proliferating Cell Nuclear Antigen; D013830:Thiadiazoles; D013963:Thyroid Hormones; C044397:N,N'-methylene-bis(2-amino-5-sulfhydryl-1,3,4-thiadiazole); D013972:Thyrotropin; D013974:Thyroxine