The comparative effects of methylmercuric chloride and mercuric chloride upon DNA synthesis in mouse fetal astrocytes in vitro.

The relative effects of direct exposure to methylmercuric chloride (MMC) and mercuric chloride (MC) upon [3H]thymidine incorporation were determined using cultured mouse fetal astrocytes. The labeling indices of cells exposed to MMC were significantly lower than those of cells exposed to equimolar concentrations of MC. These results indicate that on a mole-for-mole basis, MMC is much more deleterious upon DNA synthesis of mouse fetal astrocytes than those of MC.