Dietary subacute toxicity of ethylene thiourea in the laboratory rat
Ethylene thiourea (ETU) was fed to groups of rats at 0, 1, 5, 125 or 625 ppM for up to 90 days. Other groups of rats received either propylthiouracil (PTU; 125 ppM) or amitrole (50 ppM) in their diets as positive controls. Only those rats which received ETU at 125 or 625 ppM and those ingesting PTU or amitrole demonstrated a measurable toxic response. This toxicity was reflected as an alteration in thyroid function and a significant change in thyroid morphology. Ingestion of 625 ppM ETU or 125 ppM PTU resulted in very substantial decrease in serum triiodothyronine (T-3) and thyroxine (T-4). Marked increases in serum thyroid stimulating hormone (TSH) levels were found in the 625 and 125 ppM ETU rats, the 125 PTU rats, and the rats receiving amitrole, each time this hormone was measured. Rats which ingested 625 ppM ETU also exhibited a decrease in iodide uptake by the thyroid. While a statistically significant increase in serum T-4 and degree of thyroid hyperplasia was observed for rats ingesting 25 ppM ETU for 60 days, normal thyroid hormone levels and thyroid morphology was found in rats on 25 ppM ETU for either 30 or 90 days. Based on diochemical and microscopic changes examined, the no-effect level for dietary ETU in this 90-day study is considered to be 25 ppM.
- Research Organization:
- Battelle Columbus Labs., OH
- OSTI ID:
- 6718877
- Journal Information:
- J. Environ. Pathol. Toxicol.; (United States), Journal Name: J. Environ. Pathol. Toxicol.; (United States) Vol. 1:1; ISSN JEPTD
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
551000 -- Physiological Systems
59 BASIC BIOLOGICAL SCIENCES
62 RADIOLOGY AND NUCLEAR MEDICINE
ALKENES
AMINO ACIDS
ANIMALS
ANTITHYROID DRUGS
AZINES
BLOOD SERUM
BODY
CARBONIC ACID DERIVATIVES
CARBOXYLIC ACIDS
DIET
DOSE-RESPONSE RELATIONSHIPS
DRUGS
ELEMENTS
ENDOCRINE GLANDS
ETHYLENE
GLANDS
HALOGENS
HETEROCYCLIC COMPOUNDS
HORMONES
HYDROCARBONS
HYDROXY COMPOUNDS
INGESTION
INTAKE
IODINE
MAMMALS
MORPHOLOGY
NONMETALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANS
PEPTIDE HORMONES
PHYSIOLOGY
PITUITARY HORMONES
PYRIMIDINES
RATS
RODENTS
THIOLS
THIOURACIL
THIOUREA
THIOUREAS
THYROID
THYROID HORMONES
THYROXINE
TOXICITY
TRIIODOTHYRONINE
TSH
UPTAKE
URACILS
VERTEBRATES