Reduction of mercuric ion and exhalation of mercury in acatalasemic and normal mice.

A significant difference in the amount of exhaled mercury per hour between normal and acatalasemic mice was observed in 7 of 11 experiments for different periods of time. The total amount of mercury exhaled from acatalasemic mice was significantly higher than those of normal mice. The results confirm that the reduction of mercuric ion to metallic mercury occurs by recycling of mercury in the tissues and reoxidized metallic mercury to mercuric ion by catalase. Mercuric ion was reduced to metallic mercury in the presence of superoxide anion in vitro. The reduction rate of mercuric ion to metallic mercury in the presence of both superoxide anion and cytochrome C or nitro blue tetrazolium was higher than that in the presence of superoxide anion alone, and the reduction of mercuric ion by NADPH or NADH was also observed. The reduction of mercuric ion to metallic mercury by liver homogenates of acatalasemic mice was higher than that of normal mice.