The effect of zinc on copper in rat kidney, liver, and in metallothionein in a dose-effect study

In the present study I examined the effect of zinc (Zn) on copper (Cu) contents of kidneys, livers and metallothionein (MT) after Zn injection. Each rat was intra-peritoneally injected once with 0.9% NaCl or Zn (5, 10, or 20 mg Zn/kg BW). After Zn injection, 65.2 - 74.8% of the hepatic Zn contents, 61.0 - 63.0% of the renal Zn contents, 64.9 - 68.1% of the hepatic Cu contents, and 62.3 - 65.7% of the renal Cu contents were found in the cytosol. The Zn contents in the hepatic cytosol, the renal cytosol, livers, and kidneys increased in response to Zn injection, while no difference in the Cu contents of the hepatic cytosol and livers, was observed between the control rats and Zn-injected rats. The Cu contents of the renal cytosol and kidneys showed a decrease with increasing doses of Zn. The distribution profiles of the renal cytosol of Zn-injected rats on a Sephadex G-75 column showed that this decrease was correlated with Cu concentrations of the MT fractions. The Cu contents in the renal MT fractions of rats injected with 20 mg Zn/kg BW decreased to similar to 80% of the control rats. These results indicated that Zn injection could influence Cu contents in rat kidneys, in the renal cytosol, and in the MT fractions, but it had no effect on Cu contents in rat liver and in the hepatic cytosol.