Record Display for the EPA National Library Catalog


Main Title Dietary subacute toxicity of ethylene thiourea in the laboratory rat /
Author Freudenthal, Ralph I.
CORP Author Battelle Columbus Labs., Ohio.;Health Effects Research Lab., Research Triangle Park, N.C.
Publisher U.S. Environmental Protection Agency, Health Effects Research Laboratory,
Year Published 1977
Report Number EPA/600/1-77-023; EPA-68-02-1715
Stock Number PB-267 981
OCLC Number 42838087
Subjects Pesticides--Physiological effect
Additional Subjects Fungicides ; Toxicity ; Thyroid gland ; Rats ; Laboratory animals ; Pesticides ; Degradation ; Thyroid hormones ; Malignant neoplasms ; Pathology ; Physiological effects ; Thyroid hormones ; Histology ; Sublethal dosage ; Ingestion(Biology) ; Toxic tolerances ; Bioassay ; Permissible dosage ; Nitrogen organic compounds ; Sulfur organic compounds ; Cancer ; Histopathology ; Imidazolidine-thione ; Triazole/amino ; Thiouracil/propyl
Internet Access
Description Access URL
Library Call Number Additional Info Location Last
EJBD  EPA 600-1-77-023 Headquarters Library/Washington,DC 12/19/2014
EKBD  EPA-600/1-77-023 Research Triangle Park Library/RTP, NC 06/06/2003
ELBD ARCHIVE EPA 600-1-77-023 Received from HQ AWBERC Library/Cincinnati,OH 10/04/2023
ELBD  EPA 600-1-77-023 AWBERC Library/Cincinnati,OH 12/19/2017
NTIS  PB-267 981 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation vii, 40 pages ; 28 cm.
Ethylene thiourea (ETU) was fed to groups of rats at 0, 1, 5, 25, 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 decreases in serum triiodothyronine (T-3) and thyroxine (T-4). Marked increases in serum thryroid stimulating hormone (TSH) levels were found in the 625 and 125 ppm ETU rats, the 125 PTU rats and the rats receiving amitrole, at each time point this hormone was measured. While a statistically significant increase in serum T-4 and degree of thyroid hyperplasia was observed for the rats ingesting 25 ppm ETU for 60 days, normal thyroid hormone levels and thyroid morphology was found in the rats on 25 ppm ETU for either 30 or 90 days. The no-effect level for dietary ETU in this 90-day study is considered to be 25 ppm, equivalent to an average intake ranging from 19.5 mg/kg body weight at week 1 to 12.5 mg/kg body weight at week 12.
"EPA-600/1-77-023." EPA contract no. 68-02-1715; EPA project officer: Ronald L. Baron. Includes bibliographical references (pages 9-10).