title: Effects of zinc toxicity on thyroid function and histology in broiler chicks.
abstract: Mechanisms of zinc (Zn) toxicity are incompletely understood and data regarding potential endocrine alterations in Zn toxicity are scarce. To examine mechanisms of Zn toxicity, day-old chicks were pair-fed diets containing 5280 ppm (Hz) or 73 ppm (CON) Zn. Impaired postnatal growth, independent of feed consumption, and multiple endocrinopathies were observed following short-term (1-2 weeks) exposure to the high Zn diet. Reduced levels of serum cholesterol, high-density lipoprotein cholesterol, and growth hormone were associated with HZ feeding. Depressed levels of circulating thyroid hormones and histological evidence that follicle area of thyroids from HZ birds was 63% less than CON indicated that impaired growth of HZ birds may be caused, in part, by reduced thyroidal function.
authors.affiliation: Department of Poultry Science, Texas Agricultural Experiment Station, Texas A&M University System, College Station 77843-2472.
authors.forename: C E
authors.initials: CE
authors.lastname: Dean
authors.forename: B M
authors.initials: BM
authors.lastname: Hargis
authors.forename: P S
authors.initials: PS
authors.lastname: Hargis
mesh_terms: D000818:Animals; D002645:Chickens; D002784:Cholesterol / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood; D006128:Growth / Q000187:drug effects; D013006:Growth Hormone / Q000097:blood; D008297:Male; D013961:Thyroid Gland / Q000187:drug effects* / Q000473:pathology; D015032:Zinc / Q000008:administration & dosage / Q000633:toxicity*
chemical_list: D008076:Cholesterol, HDL; D013006:Growth Hormone; D002784:Cholesterol; D015032:Zinc