Abstract Title:

Perchlorate exposure induces hypothyroidism and affects thyroid-responsive genes in liver but not brain of quail chicks.

Abstract Source:

Arch Environ Contam Toxicol. 2009 Oct;57(3):598-607. Epub 2009 Mar 24. PMID: 19308637

Abstract Author(s):

Yu Chen, F M Anne McNabb, Jill C Sible

Article Affiliation:

Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061-0406, USA.


Ground-dwelling birds in perchlorate-contaminated areas are exposed to perchlorate ion, a known thyroid disruptor, and might be vulnerable to the developmental effects of perchlorate-induced hypothyroidism. We hypothesized that perchlorate-induced hypothyroidism would alter the expression of thyroid-responsive genes involved in thyroid hormone (TH) regulation and in the development of target organ function. Japanese quail chicks were exposed to 2000 mg/L ammonium perchlorate in drinking water for 7.5 weeks beginning on day 5 posthatch. Hypothyroidism was evident after 2 weeks of exposure as lower plasma THs and lower TH content in exposed chicks than in controls. The degree of hypothyroidism was increased at 7.5 weeks, as indicated by significant thyroid gland hypertrophy and sustained changes in thyroid function. After 2 weeks of exposure, hypothyroidism increased type 2 5'-deiodinase (D2) mRNA level and decreased Spot 14 (SP14) mRNA level in the liver, whereas D2 mRNA and RC3 mRNA levels in brain were not affected. After 7.5 weeks of exposure, mRNA levels in the exposed group did not differ from those in controls in either the liver or brain, suggesting the responsiveness of these genes to THs decreased during development. These results suggest that the brain, but not the liver, was protected from the effects of hypothyroidism, probably by changes in D2 activity at the protein level and/or regulation of TH entry and exit from the brain. We concluded that perchlorate exposure caused hypothyroidism in young Japanese quail and affected the expression of thyroid-responsive genes during early posthatch development.

Study Type : Animal Study
Additional Links
Problem Substances : Perchlorate : CK(142) : AC(33)
Adverse Pharmacological Actions : Endocrine Disruptor : CK(527) : AC(105)

Print Options

Key Research Topics

Sayer Ji
Founder of GreenMedInfo.com

Subscribe to our informative Newsletter & receive The Dark Side of Wheat Ebook

Our newsletter serves 500,000 with essential news, research & healthy tips, daily.

Download Now

The Dark Side of Wheat

This website is for information purposes only. By providing the information contained herein we are not diagnosing, treating, curing, mitigating, or preventing any type of disease or medical condition. Before beginning any type of natural, integrative or conventional treatment regimen, it is advisable to seek the advice of a licensed healthcare professional.

© Copyright 2008-2023 GreenMedInfo.com, Journal Articles copyright of original owners, MeSH copyright NLM.