Accession Number : ADA303621

Title :   Effects of Ammonium Perchlorate on the Thyroid Hormone Levels of the Sprague-Dawley Rat.

Descriptive Note : Master's thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING

Personal Author(s) : King, James H., Jr

PDF Url : ADA303621

Report Date : DEC 1995

Pagination or Media Count : 69

Abstract : The purpose of this research was to determine the threshold dose for ammonium perchlorate (AP) in the Sprague-Dawley rat. No dose response data exist for AP and the EPA has studied literature on the subject of perchlorates to determine a provisional reference dose. The Perchiorate Group, a consortium of DoD and industry representatives, believes this provisional reference dose is too conservative. This experiment was executed to provide dose response data on which to base a more accurate reference dose. The study consisted of eight groups of 12 Sprague-Dawley rats, six male and six female, which were exposed to incremental doses of AP in their drinking water. The results indicated that Triiodothyronine (T3) levels in male and female rats fell, Thyroxine (T4) levels in male rats remained relatively unchanged. Reverse Triiodothyronine (rT3), Thyrotropin (TSH), and Thyroglobulin (Tg) all increased in both males and females. These results imply that the AP anion blocked the uptake of iodine in the thyroid. Although an estimated threshold could not be determined, the NOAEL for AP on the TSH levels was .44 mg/kg/day for the male rats and .124 mg/kglday for the female rats. These NOAELs are consistent with the assumptions made by the EPA, which estimated a NOAEL of .14 mg/kg/day for perchlorates.

Descriptors :   *RATS, *TOXICITY, *DRINKING WATER, *RESPONSE(BIOLOGY), *AMMONIUM PERCHLORATE, *THYROXINE, INDUSTRIES, EXPOSURE(GENERAL), THRESHOLD EFFECTS, THYROID GLAND, THYROTROPIN, ACCURACY, ESTIMATES, DOSAGE, IODINE, MALES, FEMALES, PERCHLORATES, THYROID HORMONES, THYROGLOBULIN.

Subject Categories : Toxicology
      Biochemistry
      Inorganic Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE