The Role Of Iron Or Zinc On Nephrotoxicity Induced By Cadmium

Cadmium is one of metal toxicants with a long biological half-lifethat can bring health damage for population severely. Its toxic effectsnvolve in multiple systems and organs in human. It exists almost ineverywhere in the world that it harms population because of cadmiumexposure in occupational or general environment. More and more evidencesshow that it could result in nephric damage even under the condition ofdaily intake of cadmium in general environment eventually. Both of ironand zinc are essential microelements. Iron and zinc deficiency is popularin population because of many reasons. Dietary iron, zinc and cadmium areemulatively absorbed by divalent metal transporter 1 (DMT1) in smallintestine. This study is aimed to explore the effects of iron and zincon the Cd toxic effect and the affection of Cd on the metabolisms andfunctions of iron and zinc by human investigation and animal experiment.Animal experiment shows that iron deficiency diet can increasecadmium retention in liver; Increase of zinc content in liver anddeCreases of serum and renal zinc contents, and decreases of activitiesof SOD in liver and AKP in serum were observed when Cd was administeredby peritoneal injection; The increases ofβ₂—MG, ALB, NAG and TP in urinecan be seen when the mixture of CdCl₂ and mercaptoethanol(ME) wasadministered, these changes are highly negatively correlated with thedeCrease of zinc content in kidney but seem no direct correlationship withiron; When CdCl₂ was administered solely or mixed with ME peritoneallythe hepatic injury takes place; The increases of Cd and AKP in embryosliver, and the decreases of acetylcholine(Ach) and total antioxidativecapacity(T-AOC) in embryos brain exist when CdCl₂ was administered topregnant dams, at the same time a trend of Cd content increase and zinccontent decrease and a negative correlation between zinc and Cd contentin brain can be seen.The results of human investigation in Cd exposure workers show that the highercontents of BCd, UCd, Uβ₂-MG and UALB and lower Hb and serum ferritin contentsin exposure group are observed compared with control group under the condition thatthe Cd mean concentration in the air of industrial environment is lower than National Hygienic Sstandard; A dose dependent inCrease of UNAG, Uβ₂-MG and UALB exist;The prevalence of anemia in exposure group is higher than control group;Although there is no significant difference of BZn and UZn betweenexposure group and control group, the content of UZn is tightly positivelycorrelated with the contents of UCd and BCd, the zinc excretion in urineincreases in workers with higher UCd.In the investigation for pregnant women, Hb, BZn and SFe contents arelower and UCd, BCd, Uβ₂—MG and UNAG contents and incidence of anemia arehigher in pregnant women than that in no-pregnant women. The patients withpregnancy induced hypertention(PIH) have higher UNAG and Uβ₂-MG thancommon pregnant women and no-pregnant women. In the pregnant women, thereis a positive correlation between UCd and contractive blood pressure.There is a higher diastolic blood pressure in women with higher UCd. Allof these changes clew that Cd could be one of factors that result in PIH.There is a negative correlation between BZn and blood pressure, UNAG andUβ₂—MG. The Hb. SF and SFe are positively correlated with contractiveblood pressure and diastolic blood pressure.Conclusion: 1. Cadmium can result in changes of zinc distribution inthe body, and Pre-supplement zinc has protective effect on zinc enzyme inhibitationand LPO induced by Cd.2. The prevalence of anemia increase and nephric injury occurunder the condition that the Cd mean concentration in the air of industrialenvironment is lower than National Hygienic Standard.3. The iron status has no direct effect on cadmium nephrotoxicity,but can affect cadmium absorption in intestinal tract and indirectly affects cadmiumtoxicity by affecting zinc metabolism.4. Increase of Cd, higher level of iron status and zinc deficiencyare relative with pregnancy induced hypertention.