金属水銀の取り込みに対するカタラーゼの役割に関する研究 第4報 スーパーオキサイドアニオン,NADPH,NADH及びアカタラセミアマウス肝ホモジネートによる水銀イオンの還元

In vitro reduction of mercuric ion to metallic mercury by superoxide anion, NADPH, NADH and acatalasemic mouse liver homogenate was investigated. Superoxide anion generated by the xanthine-xanthine oxidase system reduced mercuric ion to metallic mercury in vitro. The reduction rate was inceresed linearly by the increasing concentration of xanthine oxidase. The reduction of mercuric ion by superoxide anion was increased by the addition of cytochrome c and nitro blue tetrazolium. The reduction of mercuric ion was inhibited in the presence of superoxide dismutase and catalase. The rate of reduction of mercuric ion by acatalasemic mouse liver homogenates was higher than that by normal mice liver homogenate. The reduction of mercuric ion by mouse liver homogenate was inhibited by the generation of superoxide anion, but the reduction rate by acatalasemic mouse liver homogenate was higher than that of normal mouse homogenate. NADPH and NADH reduced mercuric ion to metallic mercury. The reduction decreased in the presence of mouse liver homogenate. These results indicate that metabolism of mercury is influenced by the balance of oxidation and reduction systems