Differences in the distribution of iodine and iodide in the Sprague-Dawley rat

Journal Article · Sun Jul 01 00:00:00 EDT 1990 · Fundamental and Applied Toxicology; (USA)

DOI:https://doi.org/10.1016/0272-0590(90)90164-F· OSTI ID:6621416

Thrall, K D; Bull, R J ^[1]

---

1. Washington State Univ., Pullman (USA)

Use of iodine as a drinking water disinfectant for extended space flight raises concerns about potential chronic effects on health. A key question is whether the chemical form of iodine might play a role. To address this question the influence chemical form has on the uptake and distribution of radioiodine was studied in fed and fasted rats. Following oral administration of 125I2 or 125I-, blood 125I levels were maximal at 2 hr and reached similar concentrations in fed animals receiving 125I- and fasted animals receiving either 125I2 or 125I-. However, when 125I2 was administered to fed animals the initial levels of 125I into blood were significantly lower than after the other treatments. The half-life of elimination of 125I from the blood appeared independent of the form of iodine administered. The initial distribution of 125I to the thyroid depended sharply on chemical form, being greater when iodide rather than iodine was administered, whether animals were fed or fasted. In fed animals administered I2, this may largely be explained by the increased retention of 125I in the stomach contents. In fasted animals, both stomach content and blood levels of 125I were similar whether I2 or I- was administered. Since thyroid uptake of iodine is specific for I-, this suggests that the form of iodine in the blood was different in animals administered I2. This notion was further supported by the finding that pretreatment of animals with varying concentrations of I- in drinking water was four times as effective in suppressing the uptake of a test dose of 125I- than pretreatment with equivalent concentrations of I2.

• OSTI ID: 6621416
• Journal Information: Fundamental and Applied Toxicology; (USA), Vol. 15:1; ISSN 0272-0590
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
IODIDES
METABOLISM
IODINE
BIOLOGICAL HALF-LIFE
COMPARATIVE EVALUATIONS
DRINKING WATER
FASTING
FECES
INTESTINAL ABSORPTION
IODINE 125
ORAL ADMINISTRATION
RATS
THYROID
TISSUE DISTRIBUTION
TRACER TECHNIQUES
ABSORPTION
ANIMALS
BETA DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BIOLOGICAL WASTES
BODY
DAYS LIVING RADIOISOTOPES
DISTRIBUTION
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTS
ENDOCRINE GLANDS
GLANDS
HALIDES
HALOGEN COMPOUNDS
HALOGENS
HYDROGEN COMPOUNDS
INTERMEDIATE MASS NUCLEI
IODINE COMPOUNDS
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MAMMALS
MATERIALS
NONMETALS
NUCLEI
ODD-EVEN NUCLEI
ORGANS
OXYGEN COMPOUNDS
RADIOISOTOPES
RODENTS
UPTAKE
VERTEBRATES
WASTES
WATER
550501* - Metabolism- Tracer Techniques