Studies On The Damage Of Renal Cells Induced By Lead And Cadmium In SD Rats And The Protective Effect Of Selenium

Lead (Pb) and Cadmium( Cd) were all important environmental pollutants, they could affect human and animal's health by food-chain. The aim of the experiment is to observe the combined toxic effects of lead and cadmium on renal cells and protective effects of sodium selenite in SD rats. This study was based on SD rats's renal cells primary culture, the culture fluid was added with different concentrations of Pb (10,20,40μmol/L) or Cd (10,20,40μmol/L), and Pb-Cd combined (5,10,20μmol/L, respectively), or along with 0.5mg/L selenium as sodium selenite. After cultured for 6 hours, the cells'morphology, apoptosis rate and cell cycle were analysed by flow cytometry and electron microscope. Superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and malondialdehyde (MDA) content in culture fluid were examined. Results shows that: (1) We established a method of renal cells culture in SD rats. Through this method a large quantity renal cells were obtained,and cost litte. (2) Low concentrations of Pb or Cd (10μmol/L) have no obvious damage to cells. When the concentration was above 20μmol/L, many changes were happened. Including cells shrunk, cell volume reduced, debris on cell membrane and so on. When Pb and Cd combined administrated to cells, the damage was much more severe. (3) Low concentrations (10μmol/L) of Pb decreased cells'apoptosis rate, and when concerntrations above 20μmol/L apoptosis was increased, and the cell cycle was changed. Pb and Cd had notable synergic effcets, when their concentrations reached 40μmol/L respectively, apoptosis rate decreased greatly, necrosis rate increased. (4)Pb-Cd both can decrease the activity of GSH-Px and SOD in the culture fluid, and increased the content of MDA, the changed degrees depend on the dose quantities and cultured time. (5) When add Na₂SeO₃ to the culture fluid, the apoptosis rate was decreased, also can alleviate the decreased activity of GSH-Px and SOD, and the increased content of MDA. This indicated that Se had some protective effects for damage to renal cells caused by Pb and Cd.