In Vitro Interaction of Mercury and Selenium in Rat Plasma

Abstract

In order to elucidate the mechanisms involved in the formation of the Hg-Se complex in plasma in vivo, the interaction of mercury and selenium in rat plasma in vitro was studied by a gel filtration method. When mercuric chloride was added to rat blood within 20 min after the addition of selenite, two distinct overlapping peaks of mercury and selenium were found in the gel chromatographic fractionation of plasma. One of the overlapping peaks was found in the void volume fraction, while the other overlapping peak of both elements appeared in the elution region of the Hg-Se complex formed in plasma in vivo. When mercury was added 40 min after the addition of selenite, only the former overlapping peak appeared. When the plasma obtained from an incubation mixture of blood and selenite (incubation time : 5 or 40 min) was treated with mercury, the selenium level in the void volume fraction increased, whereas that in the albumin fraction decreased. A mercury peak appeared only in the void volume fraction. These results suggested that the latter overlapping peak of both elements was produced by the interaction of mercury with labile metabolites of selenite, other than albumin-bound selenium, existing in the blood within 20 min after the addition of selenite.