title: HTO oral administration in mice. I: Threshold dose rate for haematopoietic death.
abstract: Tritiated water in various concentrations was orally administered continuously to (C57BL/6N and C3H/He)F1 female mice in a closed animal chamber. Tritium radioactivity in various organ tissues was measured periodically after initiating tritiated water intake using an automatic sample combustion system and a liquid scintillation counter. After 7 days the specific radioactivity reached a plateau. These data allowed absorbed organ doses to be estimated. Within a range of 1.48 x 10(11) to 5.92 x 10(11) Bq/dm3 as the concentration of tritiated water in drinking water, the time of death after initiating the administration was about 2 weeks, a typical time for haematopoietic death. A linear relationship of times of death with tritiated water concentrations in drinking water was observed, on a log-log scale, between 1.85 x 10(10) Bq/dm3 and 1.48 x 10(11) Bq/dm3. At concentrations lower than 9.25 x 10(9) Bq/dm3, mice no longer died from haematopoietic failure. We conclude, therefore, that there should be a threshold dose rate for haematopoietic death.
authors.affiliation: Department of Biology, Faculty of Sciences, Hiroshima University, Japan.
authors.forename: O
authors.initials: O
authors.lastname: Yamamoto
authors.forename: K
authors.initials: K
authors.lastname: Yokoro
authors.forename: T
authors.initials: T
authors.lastname: Seyama
authors.forename: A
authors.initials: A
authors.lastname: Kinomura
authors.forename: T
authors.initials: T
authors.lastname: Nomura
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000473:pathology / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D004326:Drinking; D005260:Female; D006410:Hematopoiesis / Q000528:radiation effects*; D006412:Hematopoietic Stem Cells / Q000528:radiation effects; D008223:Lymphoma / Q000209:etiology; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D009381:Neoplasms, Radiation-Induced / Q000209:etiology; D011829:Radiation Dosage; D013997:Time Factors; D014018:Tissue Distribution; D014316:Tritium / Q000008:administration & dosage* / Q000009:adverse effects / Q000378:metabolism
chemical_list: D014316:Tritium