Modifying effect of 26-hydroxycholesterol on low-magnesium-induced atherosclerotic changes in the cultured human arterial smooth muscle cell.

This study investigated the modifying effect of 26-hydroxycholesterol (26-OHC) on low-Mg(2+)-induced atherosclerotic changes in human arterial smooth muscle cells. Cells were exposed to a medium containing a concentration of 142, 332, 665 and 949 microM Mg2+ (as control) for the designed periods. Half the cells were simultaneously exposed to 10 micrograms/ml of 26-OHC. The results showed that the cytotoxicity of low Mg2+ and the stimulating effect of low Mg2+ on cytosolic free Ca2+ level and 45Ca2+ uptake were accentuated by 26 microns OHC. The significant increase of [3H]thymidine incorporation by Mg2+ level at and lower than 332 was, however, counteracted by 26-OHC. While an increased [3H]leucine incorporation occurred only at a level of 665 microM Mg2+, an additional increase of [3H]leucine incorporation also occurred at a level of 142 microM Mg2+ in the presence of 26-OHC. We suggest that 26-OHC could modify the atherogenic effect of low Mg2+.