抄録
Rat kidney metallothionein, which contains copper as a major metal, was injected into young female rats to investigate whether the injected kidney metallothionein is degraded and re-synthesis of metallothionein occurs in the kidneys, as in the case of injected liver metallothionein. The changes in the gel filtration profiles of the kidney supernatant fractions with time could be explained by the degradation and re-synthesis of metallothionein in the kidneys. The cadmium and copper liberated from the degraded metallothionein induced the biosynthesis of metallothionein and copper-binding protein (possibly copper-thionein). The re-synthesized metallothionein was rich only in cadmium and zinc, and the half-lives of the two metals were long. On the other hand, the half-life of the copper-binding protein was short. The peak positions of the metallothionein and the copper-binding protein were different on a Sephadex G-75 column. The renal tubularlining cells were severly damaged by the injection of metallothionein. The necrosis and recovery of the kidneys were confirmed by microscopic examinations and by analysis of urinary glucose.
