Maximum Permissible Intakes of 35S-L-Methionine and 35S-Sodium Sulphate Deduced from Experiments on Rats

ICRP Publication 134: Occupational Intakes of Radionuclides: Part 2

“…Schulz (1984) reported that orally administered thiosulphate (S 2 O 3 2− ) in humans was not absorbed from the gastrointestinal tract, but thiocyanate (CNS − ) was absorbed completely. (196) Results obtained by Dziewiatkowski (1949) for the excretion of 35 S in rats after oral administration as the sulphate or sulphide indicated that absorption was 0.9 or greater. Minski and Vennart (1971) measured the absorption of [ 35 S]-methionine in rats and obtained a mean value of approximately 0.9. Elemental sulphur was found to be absorbed less well, with values in rats of approximately 0.1 (Dziewiatkowski, 1962).…”

“…Uptake in other types of cartilage and in samples of skin, fibrous tissue, and muscle was relatively low, but subsequent loss from these tissues was slow. (202) In studies of the behaviour of intravenously injected inorganic 35 S in human subjects and laboratory animals, it was found that a significant portion of the 35 S accumulated in the cartilage and bone (Denko and Priest, 1957; Buck and Heagy, 1958; Gottschalk et al., 1959). Activity depositing in these tissues was removed with a biological half-time of several days. (203) Minski and Vennart (1971) studied the biokinetics of 35 S in 76 rats following its intravenous administration as the inorganic form Na 2 35 SO 4 or the organic form 35 S-L-methionine. Following administration of inorganic 35 S, the cartilage and marrow had the greatest integrated activity per unit mass, and the soft tissue had the lowest integrated activity.…”

The transfer of different forms of 35S to goat milk

“…Indeed, in ruminants there is evidence that there is greater weight gain and retention of sulphur ingested as methionine (Peeler, 1972). Johnson et al (1971) reported higher retention of orally administered 35 S methionine than that of 35 S-sulphate by lambs; Minski and Vennart (1971) reported similar results from studies using rats.…”

“…Absorbed sulphate is rapidly excreted in rats (Minski and Vennart, 1971) whereas S in amino acids, such as methionine, is incorporated into body tissues and milk protein (Beresford et al, 1996). The incorporation of methionine into body and milk proteins would be anticipated to be higher than for other forms of sulphur.…”

Contamination atmosphérique par les produits de radiolyse des solutions aqueuses de methionine35S

“…Si l'on prend cette valeur, une contamination de 60 kBq représente alors une exposition interne inférieure à 1/500 de la LAI. Il a été montré que l'organe cible est la moelle osseuse [4].…”