Toxicity and ultrastructural localization of mercuric chloride in cultured murine macrophages

The effects of mercuric chloride on cell survival, phagocytosis and cell migration were examined in cultured mouse peritoneal macrophages, and the accumulation of mercuric chloride in the cells was visualized by autometallography and evaluated by light and electron microscopy. Macrophages exposed to mercury concentrations from 1.25 microM to 10 microM mercuric chloride showed a concentration- and time-dependent increase in mercuric chloride accumulation, while cells exposed to 20 microM and 40 microM mercury showed an inverse relationship between mercury concentration and the accumulation of mercury. Mercury concentrations above these levels caused cell necrosis. Electron microscopy revealed that mercury was located primarily within lysosomes but also in the nucleus and cytoplasm. Mercury increased the death rate of macrophages in a concentration-dependent manner when cells were treated with mercury concentrations not causing cell necrosis. Further, we found that mercury clearly impaired macrophage random migration and possibly the capability for phagocytosis.