Experimental studying the effects of sodium selenite on oxidative damage of liver and kidney induced by cadmium and mercury

Objective:To study the oxidative damage of liver and kidney induced by cadmium and mercury administrated once and to observe the effects of sodium selenite(Na2SeO3) pretreatment on the oxidative damage of liver and kidney of rats exposed to cadmium and mercury.Methods:48 Wistar rats were divided into six groups.Control group was injected sc with NaCl;Cadmium chloride group was injected sc with 35μmol/kg CdCl2;Others were pretreated by administering ip injection of 10μmol/kg Na2SeO3 2 hour before the injection of CdCl2.The mercury group rats were subcutaneously(sc) injected with 2.5 mg/kg HgCl2.The Na2SeO3pretreatment group rats were injected with 20 μmol/kg Na2SeO3 by abdominal cavity,and then two hours later sc administrated with 2.5 mg/kg HgCl2.The control group rats were sc injected with saline at corresponding time.24 hours after the last injection,liver and kidney cortex were collected.MDA and GSH contents in liver and renal cortex as well as GSH—Px acivities were measured.Results:Compared with control group,Cd contents in both liver and renal cortex with Cd alone were obviously increased.GSH,MDA contents in liver were increased significantly and GSH—Px activities were obviously decreased with Cd alone.The pretreatment of Na2SeO3 decreased the GSH and Cd contents in both liver and renal cortex significantly.It also obviously increased GSH—Px activities in liver and MDA contents in renal cortex as compared with those given Cd alone.The concentrations of GSH,GSH—Px in the liver were higher significantly than 2.5 mg/kg HgCl2 group.The content of MDA in liver was significantly lower than 2.5 mg/kg HgCl2 group.The concentration of GSH—Px in renal cortex of Na2SeO3 pretreatment rats was higher than that of 2.5 mg/kg HgCl2 groups alone.The others had no different with 2.5 mg/kg HgCl2 groups.Conclusions:Na2SO3 pretreatment had antagonistic effects on oxidative damage in liver induced by cadmium and mercury,which may relate to increase the content of GSH and the activities of GSH—Px.