title: Interactions of cadmium and selenium in rat plasma in vivo and in vitro.
abstract: 75Se and 109Cd tracers were used to study the binding of Se and Cd to plasma proteins at various SeO32- doses and times upt to 24 h after the simultaneous subcutaneous administration of SeO32- markedly increased both Se and Cd plasma levels over that in control animals. Gel permeation chromatography of plasma indicated that at all times up to 24 h Cd and Se were bound in an atomic ratio of approx. 1 : 1 in 330 000 and 130 000 dalton fractions. From 4 to 24 h, Cd and Se appeared in the 420 000 dalton fraction, also with an atomic ratio of approx. 1 : 1. The 330 000 dalton molecules appeared to have a maximal binding capacity for the Cd-Se complex at a concentration of approx. 30 mumol/ml of plasma, while the 130 000 and 420 000 dalton molecules show a higher binding capacity. Studies in vitro revealed that SeO32- does not interact directly with Cd and plasma proteins. It is metabolized by erythrocytes to a form that interacts in an atomic ratio of 1 : 1 with Cd to form a protein-bound complex of 130 000 daltons.
mesh_terms: D000818:Animals; D001798:Blood Proteins / Q000378:metabolism; D002104:Cadmium / Q000097:blood* / Q000494:pharmacology; D002850:Chromatography, Gel; D004347:Drug Interactions; D066298:In Vitro Techniques; D008297:Male; D051381:Rats; D012643:Selenium / Q000097:blood* / Q000494:pharmacology; D013997:Time Factors
chemical_list: D001798:Blood Proteins; D002104:Cadmium; D012643:Selenium