The cytotoxicity of cadmium ions small doses in culture of rats bone marrow cells

Abstract

It is known that cadmium ions have the property of accumulating in cells, leading to disturbances in their metabolism. The purpose of this work was to assess the cytotoxicity effects and degree of DNA damage in bone marrow cell culture from the femur of rats during prolonged cultivation in a medium containing small doses of cadmium ions – 0.1; 0.5; 1.0; 10 μM/liter of culture medium. The extent of cell adhesion and their morphology, culture density, cell membrane integrity, and the number of apoptotic cells were analyzed. The extent of DNA damage was assessed by the number of micronuclei, fragmentation of nuclear DNA in cells. It has been shown that prolonged exposure to cadmium ions in concentrations of 0.1; 0.5; 1.0 and 10 μM/L on bone marrow cells in vitro has a pronounced cytotoxic effect, and the degree of damage depends on the exposure time and the concentration of the toxicant. Exposure to cadmium for 30 days at a concentration of 0.1 and 0.5 μM/L leads to a low decrease in cell adhesion, does not lead to their average size change and serious damage to the plasma membrane. Exposure to cadmium for 30 days at a concentration of 0.1 and 0.5 μM/L leads to an increase in the number of cells in the early apoptosis stage (by 11% and 15% respectively), which is reversible and does not affect the fragmentation of nuclear DNA. Exposure to cadmium in concentrations of 1.0 and 10.0 μM leads to a significant reduction in cell adhesion, a decrease in the average cell size by 1.3 and 1.8 times, respectively, to severe damage of the cell membrane. With an increase in the concentration of Cd2+ to 1.0 and 10.0 μM/L, the number of cells with an intact membrane decreases by 27% and 50%, respectively. When exposed to cadmium ions at a concentration of 1.0 and 10.0 μM/L the proportion of cells found at both early and late stages of apoptosis increases on the 10 and 4 days of observation, respectively. By 30 days of observation it has been shown, that exposure to cadmium at a concentration of 1.0 and 10.0 μM leads to a significant increase in the number of cells in the irreversible stage of late apoptosis. It has been found, that prolonged exposure to cadmium ions in concentrations of 0.5; 1.0 and 10 μM/L per bone marrow cells in vitro has a clear genotoxic effect: the number of micronuclei and the degree of DNA fragmentation increase.