title: γ-Aminobutyric acid ameliorates fluoride-induced hypothyroidism in male Kunming mice.
abstract: OBJECTIVE
  This study evaluated the protective effects of γ-aminobutyric acid (GABA), a non-protein amino acid and anti-oxidant, against fluoride-induced hypothyroidism in mice.
  
  
  METHODS
  Light microscope sample preparation technique and TEM sample preparation technique were used to assay thyroid microstructure and ultrastructure; enzyme immunoassay method was used to assay hormone and protein levels; immunohistochemical staining method was used to assay apoptosis of thyroid follicular epithelium cells.
  
  
  RESULTS
  Subacute injection of sodium fluoride (NaF) decreased blood T4, T3 and thyroid hormone-binding globulin (TBG) levels to 33.98 μg/l, 3 2.8 ng/ml and 11.67 ng/ml, respectively. In addition, fluoride intoxication induced structural abnormalities in thyroid follicles. Our results showed that treatment of fluoride-exposed mice with GABA appreciably decreased metabolic toxicity induced by fluoride and restored the microstructural and ultrastructural organisation of the thyroid gland towards normalcy. Compared with the negative control group, GABA treatment groups showed significantly upregulated T4, T3 and TBG levels (42.34 μg/l, 6.54 ng/ml and 18.78 ng/ml, respectively; P<0.05), properly increased TSH level and apoptosis inhibition in thyroid follicular epithelial cells.
  
  
  CONCLUSIONS
  To the best of our knowledge, this is the first study to establish the therapeutic efficacy of GABA as a natural antioxidant in inducing thyroprotection against fluoride-induced toxicity.
authors.affiliation: Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Marine Science and Technology National Laboratory, Qingdao 266071, China.
authors.forename: Haoyue
authors.initials: H
authors.lastname: Yang
authors.affiliation: Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Marine Science and Technology National Laboratory, Qingdao 266071, China. Electronic address: xingronge@qdio.ac.cn.
authors.forename: Ronge
authors.initials: R
authors.lastname: Xing
authors.affiliation: Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Marine Science and Technology National Laboratory, Qingdao 266071, China.
authors.forename: Song
authors.initials: S
authors.lastname: Liu
authors.affiliation: Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Marine Science and Technology National Laboratory, Qingdao 266071, China.
authors.forename: Huahua
authors.initials: H
authors.lastname: Yu
authors.affiliation: Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Marine Science and Technology National Laboratory, Qingdao 266071, China. Electronic address: pcli@qdio.ac.cn.
authors.forename: Pengcheng
authors.initials: P
authors.lastname: Li
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D004847:Epithelial Cells / Q000187:drug effects / Q000473:pathology; D005459:Fluorides; D018682:GABA Agents / Q000627:therapeutic use*; D007037:Hypothyroidism / Q000139:chemically induced* / Q000473:pathology / Q000517:prevention & control*; D008297:Male; D051379:Mice; D010710:Phosphates; D013961:Thyroid Gland / Q000473:pathology; D013974:Thyroxine / Q000097:blood; D056825:Thyroxine-Binding Globulin / Q000378:metabolism; D014284:Triiodothyronine / Q000097:blood; D005680:gamma-Aminobutyric Acid / Q000627:therapeutic use*
chemical_list: D018682:GABA Agents; D010710:Phosphates; D056825:Thyroxine-Binding Globulin; D014284:Triiodothyronine; C012980:fluorophosphate; D005680:gamma-Aminobutyric Acid; D013974:Thyroxine; D005459:Fluorides
keywords: Ameliorative effect; GABA; Hormones; Hypothyroidism; Thyroid function