Cadmium chloride-induced oxidative stress in skeletal muscle cells in vitro

Abstract

The effects of cadmium chloride (CdCl 2) on oxidative stress in the skeletal muscle cell line C 2C 12 were investigated. Myoblast cells that differentiated into myotubes were treated with CdCl 2 (1, 3, 5, 7.5, 10, and 12.5 μM) for 24, 48, and 72 h. Subsequent assay of cell homogenates for MTT (3-(4,5-dimethylthiozol-2-yl)-2,5-diphenyltetrazolium bromide) reduction, neutral red uptake and nucleic acid content showed that cadmium was toxic to C 2C 12 cells in a concentration-dependent manner. Glutathione-S-transferase activity (nmol μg of protein −1 min −1) was increased with 1 and 3 μM CdCl 2 (36.9 ± 5.6 and 32.1 ± 6.0, respectively) compared to control cells (21.8 ± 1.5), but decreased at higher concentrations (7.5 μM = 15.9 ± 3.3, 10 μM = 15.9 ± 4.6, and 12.5 μM = 10.5 ± 2.8). An increase in malondialdehyde content (nmol μg of protein −1), especially at high CdCl 2 concentrations (control = 7.3 ± 0.5; CdCl 2: 7.5 μM = 11.2 ± 3.1, 10 μM = 14.6 ± 3.8, and 12.5 μM = 20.5 ± 6.5) indicated that there was enhanced lipid peroxidation. Light and scanning electron microscopy showed that there was a concentration-dependent loss of adherent cells and the formation of vesicles indicative of cell death. These results indicated that CdCl 2 increased oxidative stress in C 2C 12 cells, and this stress probably compromised cell adhesion and the cellular antioxidant defense mechanisms.