Histochemical localization of autometallographically detectable mercury in tissues of the immune system from mice exposed to mercuric chloride.

The distribution of mercury in the spleen, liver, lymph nodes, thymus and bone marrow was studied by autometallography in mice exposed to mercuric chloride intraperitoneally. Application of immunofluorescence histochemistry and an autometallographic silver amplification method was employed to the same tissue section. Mercury was not only detected in macrophages marked by the antibody M1/70 but also in macrophage-like cells, which were either autofluorescent or devoid of fluorescent signals. These two cell types were identified as macrophages at the electron microscopical level. Autometallographically stained macrophages were observed in the spleen, lymph nodes, thymus and in Kupffer cells of the liver. Furthermore, mercury was observed in endothelial cells. No obvious pathological disturbances were observed at light and electron microscopical level. At the subcellular level mercury was localized in lysosomes of macrophages and endothelial cells.