Tritium ( 3 H) Retention In Mice

Abstract

The objective of this study was to compare the biokinetics of injected H-labeled light (HTO) and heavy (DTO) water in CBA/CaJ mice and to compare the organ distribution and/or body content of H administered by chronic ingestion for 1 mo to C57Bl/6J mice, as either H-labeled water or H-labeled amino acids (glycine, alanine and proline). HTO and DTO were administered to CBA/CaJ mice by single intraperitoneal injection and body retention was determined for up to 384 h post-injection. Tritium-labeled water or H-labeled amino acids were given to C57Bl/6J mice ad libitum for 30 d in drinking water. Body content and organ distribution of H during the period of administration and subsequent to administration was determined by liquid scintillation counting. No differences were found between the biokinetics of HTO and DTO, indicating that data generated using HTO can be used to help assess the consequences of H releases from heavy water reactors. The results for H-water showed that the concentration of radionuclide in the mice reached a peak after about 10 d and dropped rapidly after the cessation of H administration. The maximum concentration reached was only 50% of that in the water consumed, indicating that mice receive a significant fraction of their water from respiration. Contrary to the findings of others, the pattern of H retention following the administration of a cocktail of the labeled amino acids was very little different from that found for the water. This is consistent with the suggestion that most of the ingested amino acids were rapidly metabolized, releasing water and carbon dioxide.

Hto, Tritiated Amino Acid Exposure and External Exposure Induce Differential Effects on Hematopoiesis and Iron Metabolism

“…Therefore, at the level of micro-dosimetry, one cannot exclude that local concentrations of TAA may occur in the enterocytes, thus contributing to the appearance of cell damage. Such a local concentration of TAA might not be observed in biokinetics experiments when measuring tritium content of the whole intestine, as previously described 44 . We hypothesize that in the intestine, this cell damage manifests as a decreased ferritin expression, resulting in defective iron transport in the intestinal epithelium (Fig.…”

“…These results underline the importance of the tritium speciation. Actually, HTO is distributed homogeneously in the body, mostly in the exchangeable water compartment, as previously described 44 . As a result, the dose distribution is also quite homogeneous, especially if one considers the very short range of beta particles emitted by tritium disintegration (<6 µm) 6 .…”

Effect of internal contamination with tritiated water on the neoplastic colonies in the lungs, innate anti-tumour reactions, cytokine profile, and haematopoietic system in radioresistant and radiosensitive mice

“…For our purposes, we employed one of the routinely used experimental models in which mice are i.p. injected with HTO (Priest et al 2017 ; Umata et al 2009 ). Such a route of contamination assures fast and relatively uniform distribution of the radioisotope throughout the body and enables a more precise estimation of the absorbed doses of radiation than after ingestion of tritium orally or through inhalation.…”

Effects of Chronic Low-Dose Internal Radiation on Immune-Stimulatory Responses in Mice

“…High concentration HTO was diluted in reverse osmosis (RO) water to create the mouse drinking water concentrations of 4.5, 45.5, and 910 MBq/L, providing the respective total doses of 10, 100, and 2000 mGy over the 56 day ingestion period. The tritium concentrations for mouse drinking water were calculated based on previous research at CNL, which measured the tritium retention in mouse tissues during chronic tritium exposure [ 56 ]. Tritium measurements were performed using a Liquid Scintillation Counter (Tricarb 210TR, Perkin Elmer, Waltham, MA, USA) and Ultima Gold scintillation fluid (Perkin Elmer, Waltham, MA, USA).…”

“…During this study, Tritium ( 3 H) was used as a source of radiation due to substantial public concern for potential health effects and the growing international attention [ 53 ]. This isotope of hydrogen is a by-product of the nuclear industry and was found to have effects on the biological system during recent investigations at CNL [ 54 , 55 , 56 ]. To the best of our knowledge, this is the first study that investigates the effects of internal beta LDR on the immune system in an in vivo model of spontaneous tumorigenesis.…”