Mercury in the dorsal root ganglia of rats treated with inorganic or organic mercury.

Autometallographic silver amplification has been used to demonstrate the localization of mercury deposits in rat dorsal root ganglia after repeated intraperitoneal injections of mercuric chloride or methylmercuric chloride. The silver-enhanced mercury deposits were demonstrated with the light and electron microscope. The degree of intracellular staining of the individual cells depended on the mercury compound and total dosage. Ganglion cells (types A and B) and macrophages were found to accumulate mercury after a total dosage of 400 micrograms HgCl2. After 600 micrograms HgCl2, satellite cells, endothelial cells and fibroblasts were additionally found to contain mercury deposits. Treatment with 6000 micrograms CH3HgCl caused faint staining of type A and B ganglion cells and fibroblasts. Macrophages, however, were the most heavily stained cells after treatment with CH3HgCl. Ultrastructurally, mercury was exclusively located in lysosomes. This was irrespective of the cell type and mercury compound used for treatment.