EN
Marciniak, M., Bałtrukiewicz, Z. and Chaś, J.: 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. Acta physiol. pol., 1988; 39 (4): 294-299. 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 (¹⁴ C-aminoisobutyric acid - AIB, ³ H-thymidine and ¹²⁵ I-albumin). Increased uptake of ¹⁴ C-AIB and ³ H-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. No disturbances were shown in the function of the placental barrier (which would have caused increased passage of these markers to the fetus), and rupture of the cell membranes in the studied tissues was not demonstrated. (it would have caused increased passage of ¹²⁵ I-albumin, a macromolecular compound) in any of the studied organs in mice.