Incorporation and distribution of tritium in rats after chronic exposure to various tritiated compounds.
Rats were chronically exposed to tritiated water (3HHO) and several tritiated organic compounds [( 3H]leucine, [3H]lysine, [3H]glucose, [3H]glucosamine, [3H]thymidine and [3H]uridine) dissolved in their drinking water. An analysis of tritium in wet and dry tissues of rats at the end of 22 days' chronic exposure showed that the chemical form of the ingested tritium was more important for tritium uptake in dry tissues than in wet tissues. The concentrations of tritium in dry tissues (organically bound tritium: OBT) after the exposure to tritiated organic compounds were consistently higher than after the exposure to 3HHO. The highest concentrations of OBT were found in rats exposed to tritiated amino acids [( 3H]lysine and [3H]leucine), which were 4-9 times higher than those in rats exposed to 3HHO. The next higher concentrations of OBT were found in rats exposed to [3H]uridine. The result of radiation dose estimations at the end of chronic exposure showed that the contribution of OBT to the total dose rate was higher in the tissues of rats exposed to tritiated organic compounds than that after the exposure to 3HHO. However, the differences between the total dose rates from 3HHO and those from tritiated organic compounds were within a factor of 2.
Takeda
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Division of Environmental Health, National Institute of Radiological Sciences, Chiba-shi, Japan.
D000818:Animals; D005944:Glucosamine / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D007930:Leucine / Q000378:metabolism; D008239:Lysine / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013936:Thymidine / Q000378:metabolism; D013997:Time Factors; D014018:Tissue Distribution; D014316:Tritium / Q000493:pharmacokinetics*; D014529:Uridine / Q000378:metabolism; D014867:Water / Q000378:metabolism
D014867:Water; D014316:Tritium; D007930:Leucine; D005947:Glucose; D008239:Lysine; D005944:Glucosamine; D013936:Thymidine; D014529:Uridine