Binding of Simultaneously Administered Inorganic Selenium and Mercury to a Rat Plasma Protein 1

Abstract

Summary

Simultaneous administration of 5 μmoles of HgCl₂ and of SeO₃ ^2-/kg along with traces of ²⁰³HgCl₂ and ⁷⁵SeO₃ ^2- to a rat radically alters plasma protein binding of ⁷⁵Se and ²⁰³Hg from that found when each element is given alone. After simultaneous administration both elements are present in the plasma in much greater quantities due to their binding to a single plasma protein. When the doses of the elements are varied the molar ratio of selenium to mercury in the protein remains close to 1. Dialysis data suggest that selenium is attached to a sulfhydryl group of the protein and that mercury is attached to selenium. This protein may play a role in preventing acute inorganic mercury toxicity by preventing a large part of the mercury dose from reaching target tissues.