Document Detail


Effects of a six-week exposure to excess iodide on thyroid glands of growing and nongrowing male Fischer-344 rats.
MedLine Citation:
PMID:  7915429     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
A 6-wk exposure to excess iodide intake (EII) via drinking water (260 mg potassium iodide/L) demonstrated different effects on growing (4-wk old) and nongrowing (45-wk old) male Fischer-344 rats. In growing rats, EII induced a significant increase in thyroid weight, pituitary weight, serum thyroid-stimulating hormone (TSH), and thyroxine (T4). The labeling index (LI) of thyroid follicular cells was slightly increased, although not statistically significant. Histologically, an increase in follicular cell height, an increase in colloid accumulation, and evidence of colloid absorption were noted. The effect of bovine TSH (bTSH) and protirelin tartrate (TRH-t) on LI was significantly augmented by EII. In nongrowing rats, EII induced a significant increase in thyroid weight and serum T4 but no increase in pituitary weight, serum TSH, and the LI of follicular cells. Histologically, an increase in colloid accumulation was found in small follicles. EII did not augment the effect of bTSH and TRH-t on the LI of follicular cells. This study suggests that growing rats are still susceptible to acute hypothyroidism even after 6 wk of continuous exposure to excess iodide, whereas nongrowing rats are refractory within an equivalent treatment period.
Authors:
J Kanno; T Nemoto; T Kasuga; Y Hayashi
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Toxicologic pathology     Volume:  22     ISSN:  0192-6233     ISO Abbreviation:  Toxicol Pathol     Publication Date:    1994 Jan-Feb
Date Detail:
Created Date:  1994-09-26     Completed Date:  1994-09-26     Revised Date:  2009-07-01    
Medline Journal Info:
Nlm Unique ID:  7905907     Medline TA:  Toxicol Pathol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  23-8     Citation Subset:  IM    
Affiliation:
Department of Pathology, Faculty of Medicine, Tokyo Medical and Dental University, Japan.
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MeSH Terms
Descriptor/Qualifier:
Aging / physiology
Animals
Autoantigens / metabolism
Male
Nuclear Proteins / metabolism
Organ Size / drug effects
Pituitary Gland / drug effects,  growth & development
Potassium Iodide / toxicity*
Proliferating Cell Nuclear Antigen
Rats
Rats, Inbred F344
Thyroid Gland / cytology,  drug effects*,  growth & development
Thyrotropin / blood
Thyrotropin-Releasing Hormone / blood
Chemical
Reg. No./Substance:
0/Autoantigens; 0/Nuclear Proteins; 0/Proliferating Cell Nuclear Antigen; 24305-27-9/Thyrotropin-Releasing Hormone; 7681-11-0/Potassium Iodide; 9002-71-5/Thyrotropin

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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