[Studies on the behavior of mercury and selenium in blood of mice injected with those elements]

Male ddY mice were only once treated with, 1) mercuric chloride or methylmercuric chloride (20 mumol/kg, i.p., respectively) and various doses of sodium selenite (5, 20, and 40 mumol/kg, s.c., respectively) at the same time, 2) mercury compounds alone, and 3) various doses of sodium selenite alone. Then, the interaction between mercury and selenium was investigated in the blood and plasma at 1, 5, 24, 120, and 240 hr after injection. In mice receiving mercuric chloride and sodium selenite at the same time, the concentrations of mercury and selenium in the blood and plasma were markedly higher than those in mice receiving mercuric chloride or sodium selenite alone, especially at 1 and 5 hr after injection. In this case, mercury concentrations were increased depending on doses of sodium selenite. Furthermore, their decrement from 5 to 24 hr were markedly in groups with larger quantity of mercury accumulation. In the case of simultaneous injection of methylmercuric chloride and sodium selenite, the accumulation levels of mercury in the blood and plasma decreased by the simultaneous injection of selenium at 1 and 5 hr. The molar ratios of selenium to mercury in the blood and plasma simultaneously injected with mercuric chloride and sodium selenite were approx. 1 at 5 and 24 hr, independently of any change of sodium selenite doses. In gel filtration by Sephadex G-200 column of plasma of mice simultaneously injected mercuric chloride and sodium selenite, mercury reacted with selenium immediately after their injection, and the almost of them were bound and accumulated in the high-molecular weight fraction with the molar ratios (Se/Hg) of approx. 1 until about 24 hr after injection. After 24 hr of injection, however, the binding between mercury and selenium was significantly changed and their gel-filtration patterns were similar to those of each single dose group. These results suggested that mercury and selenium in the group of simultaneous injection of mercuric chloride and sodium selenite have different interaction in blood before and after 24 hr of injection.