The effects of different doses of zinc on oxidant-antioxidant system in rat various tissues

In our study we aimed to investigate the zinc role on the oxidantantioxidant system and histological findings at the absence of oxidative stress in rat liver, kidney and brain tissues with the dose dependent manner. Thirty-nine healthy rats were divided into 4 groups; control group (ad libitum (AL) diet, (n=9)), low dose zinc group (AL diet plus 3mg/kg oral Zn sulfate, n=10), middle dose zinc group (AL diet plus 12mg/kg oral Zn sulfate, n=10) and high dose zinc group (AL diet plus 25 mg/kg oral Zn sulfate, n=10). After 13 days rats were sacrificed and livers, kidneys and brains were removed. MDA, AOPP, SOD, GPx, GR were measured. Liver MDA levels were increased low and high dose zinc groups, AOPP levels and GST activities were decreased in all zinc groups, SOD and GSH-Px activities were increased in all zinc groups , GR activities were increased in middle dose group when compared to the control group (p<0,05). Kidney AOPP lewels were decreased in low dose zinc group and increased in high dose zinc gruop, SOD activities were decreased in middle and high dose zinc groups, GR avtivities were increased in all zinc groups when compared to the control group (p<0,005). MDA levels, GSH-Px and GST activities were insignificant in all zinc groups when compared to the control group. Brain AOPP levels, GSH-Px and GR activities were decreased in all zinc groups when compared to the control group (p<0,05). SOD activities were increased in middle dose zinc group and GST activities were decreased in low dose zinc group when compared to the control group (p<0,05). However MDA levels were insignificant changed in all groups when compared to the control group. Towards our results, because of the short time zinc administration effects both oxidant and antioxidant effects and also because of these effects change tissue to tissue, we can suggest that the zinc products may be use more carefully in healthy people.