Cadmium-induced Liver Cell Toxicity And Intracellular Calcium Signal Offset The Protective Effect Of The Relationship Between Selenium

The present paper studied systematically, through animal model with primary cultured neonatal mouse hepatocytes, effects of hepatocytes injury induced by cadmium on the activities of lactate dehydrogenase (LDH) and aspartate aminotransferase (AST) as well as albumin and Ca²⁺ contents in the cultured medium, cell survivability, intracellular free Ca²⁺ concentration ([Ca²⁺]_i) and malondialdehyde (MDA) content as well as activities of Ca²⁺-Mg²⁺-ATPase and Na⁺-K⁺-ATPase in hepatocytes were investigated by means of techniques from cell culture in vitro, spectrofluorometer, confocal laser microscope and conventional biochemical assays. Mechanism of cytotoxicity and dysfunction of intracellular Ca²⁺ homeostasis in hepatocytes injury induced by Cadmium was discussed deeply. Meanwhile, the intervenient effects of selenium (Se) on Cd's hepatotoxicity also were studied. The results were summarized as follows:1. Establish of primary culture method in neonatal mouse hepatocytesHepatocytes from hepatic tissue in neonatal mice were isolated by Type IV collagenase and cultured by serum-free HepatoZYME-SFM medium. The primary hepatocytes were confirmed by morphologic observation and trypan blue dye. Survival rate of hepatocytes was above 90% and the survival hepatocytes with intact and spheric-shape were motionlessly attached to the bottom of the culture plates. The methods of isolation and culture of neonatal mouse hepatocytes were successful and perfect and make it important in a great deal of research fields.2. Studies on cadmium-induced hepatocellular toxicity and changes of intracellular free Ca²⁺ concentrationPrimary cultured neonatal mouse hepatocytes were divided randomly into three treatment groups and a normal control group which were given HepatoZYME-SFM medium containing 5, 10, 25 μmol/L cadmium chloride (CdCl₂) and the same dosage of D-hank's solution. The results showed that after CdCl₂ challenge, the cell survivability decreased, showing a dose-dependent manner. The release of LDH and AST markedly increased and albumin concentration in the culture medium notably decreased after 12 h. The formation of MDA enhanced and maintained at an extremely high level, while the Ca²⁺ concentrations of cultured medium in three CdCl₂-exposed groups evidently decreased in comparison with that in control group.