Influence of cadmium on structure and functions of mitochondria in hepatic cells
Zhang, N.-n.; Mao, W.-p.; Wei, C.-j.; Zhou, L.; Liu, H.-y.; Feng, J.
Zhonghua Yi Xue Za Zhi 88(19): 1350-1353
2008
ISSN/ISBN: 0376-2491 PMID: 18956708 Document Number: 616983
To study the effects of cadmium on the structure and functions of mitochondria in hepatocytes. Mitochondria were isolated from cultured human hepatocytes of the line WRL-68 and co-cultured with cadmium chloride (CdCl2) of the concentration of 1, 5, and 10 micromol/L, and WRL-68 cells not treated with CdCl2 (0 micromol/L) was used as control group. Cyclosporin A (CsA) was added into the culture medium. Mitochondrial permeability transition pore (MPTP) opening degree was tested by spectrophotometer. Morphologic changes of mitochondria were observed under transmission electron microscope. The activities of Na+ -K+ -ATPase, Ca2+ -Mg2+ -ATPase, LDH, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and the contents of malondialdehyde (MDA) were measured Mitochondria membrane potential (MMP) was monitored by spectrofluorimeter with fluorescence dye Rh-123. CdCl2 reduced the absorbance of mitochondria, signifying the opening of MPTP, concentration-dependently. The absorbance of mitochondria co-cultured with CsA and CdCl2 10 micromol/L was higher than that of the. CdCl2, 10 micromol/L group. Mild swelling was seen in the mitochondria treated with CdCl2. The MMP values of the CdCl2 5 and 10 micromol/L groups were significantly lower than that of the control group (P < 0.05, P < 0.01). The activity levels of ATPase, LDH, SOD, and GSH-Px in mitochondria decreased in the CdCl2 groups (all P < 0.05), and the contents of MDA increased in the CdCl2 groups compared with the control group. CdCl2 causes destruction of mitochondria structure, opening of MPTP, decrease of MMP, and changes of vitality of mitochondria enzymes that all play important roles in apoptosis of hepatocytes.