الفهرس 
CadmiumOnly 14 pages are availabe for public view
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Abstract
This study aimed to determine the effects of supplementation of both Zn and Cd on the activities of some antioxidant enzymes as well as the effect of these metals on the levels of Metallothionein (Mt) protein. In order to achieve the aim of the study, forty eight male wister albino rats weighted 200 gram divided into four equal groups. Group I (Control Group) was fed on normal control diet, while Group II (Zn supplemented Group) was supplied with 180 mg zinc chloride/kg of control diet. Group III (Cd supplemented Group) was supplied with 8.8mg CdCL2/kg of control diet. Group IV (Zn and Cd supplemented Group) was supplied by a mixture of both zinc and cadmium chloride doses/Kg of control diet. At the end of the experiment, the result revealed that combination of both Cd and Zn caused in a decrease of Cd concentration in Group IV when compared with Group III in blood, kidneys and liver which revealed the role of Zn in ameliorating the toxic effect of Cd. Zn supplementation resulted in an increase in blood SOD and GST activity, GSH and Mt concentration with a depression in CAT activity. Cd supplementation resulted in a depression in SOD activity and GSH concentration, while there was an increase in CAT, MT concentration and GST activity of rats in treated group. Zn was considered the most important inducer of Mt protein in kidneys and blood, while combination of both Zn and Cd achieved the higher induction of Mt protein in liver, hence Mt protein was induced by adding Zn and Cd either alone or in combination which reflects its sensitivity as a pollution biomarker. Mt protein localization was showed the same trend as in Mt protein concentration in kidneys and liver in which Zn treated rats showed the highest localization of Mt protein in kidneys. In liver, the combination of both Cd and Zn would result in the highest Mt protein localization. It was found that total RNA concentration was correlated with the content of heavy metals and mRNA relative density in kidneys in Group IV, while in liver total RNA concentration was correlated with the accumulation of heavy metals and Mt mRNA relative density in Group III. Mt I and II gene expression in kidneys showed a dissimilar pattern from both Mt protein concentration and Mt protein localization in which the combined treatment with Cd and Zn showed the highest Mt I and II mRNA relative density. In liver, Mt I and II mRNA showed the highest relative density in rats treated with both Cd and Zn as well as the single metal treatment showed also an increase in Mt I and II mRNA relative density in comparison with the control group.