Transport of lanthanides in milk into suckling rats.

The aim of this paper was to examine the transport of lanthanides in milk of contaminated rats into their sucklings and the retention of lanthanides in the sucklings. The research involved 55 female Wistar rats contaminated in the period of lactation and their offspring (400 infant rats). The study showed that in the period of lactation the transport in milk from the mother to the offspring of the lanthanide radionuclides under examination (144Ce, 147Nd, 152Sm, 155Eu and 160Tb) increased with their mass numbers: CE < Nd < Sm < Eu < Tb, and varied from 0.

The effect of toxic doses of lanthanum and cerium on the placental barrier and the blood/organ barrier in mice after intravenous injection of these elements.

In earlier studies the toxicity of the lanthanides was determined on the basis of the LD50/30 value, increase of serum ornithine carbamoyltransferase activity, and the degree of passage of the lanthanides to the fetuses and milk. The purpose of the present work was to investigate the effects of toxic doses of lanthanum and cerium on the function of the placental barrier and the blood/organ barrier in mice using substances of known molecular weight labelled with radionuclides (14C-aminoisobutyric acid--AIB, 3H-thymidine and 125I-albumin). Increased uptake of 14C-AIB and 3H-thymidine was demonstrated in the liver, spleen and placenta of mice after toxic doses of La and Ce indicating disturbances in the function of the blood/organ barrier (liver, spleen, placenta) due to damage to the vascular endothelium or cell membranes.

Estimation of I131 doses absorbed by the thyroid in the period from May to June 1986.

In a randomly selected group of subjects the uptake of iodine radioisotopes was measured over the thyroid in the period May 6-23, 1986. From the obtained results the doses were estimated which were absorbed from April 28, 1986 until the time of complete disappearance of I131 from the thyroid. The highest dose of radiation absorbed from I131 by the thyroid was found in the youngest group (children aged 5 to 12 years) and it was 227.