Silver amplification of mercury sulfide and selenide: a histochemical method for light and electron microscopic localization of mercury in tissue.

Abstract

A method for light and electron microscopic demonstration of mercury sulfides and mercury selenides in mammalian tissue is presented. Silver ions adhering to the surface of submicroscopic traces of mercury sulfides or selenides in the tissue are reduced to metallic silver by hydroquinone. Physical development thereupon renders deposits of mercury sulfides or mercury selenide visible as spheres of solid silver. Examples of localization of mercury in the central nervous system and various organs from animals exposed to mercury chloride or methyl mercury chloride with or without additional sodium selenide treatment are presented. Selenium treatment results in a considerable increase in the amount of mercury that can be made visible by silver amplification. After mercury chloride treatment, most of the mercury is localized in lysosomes and is only rarely seen in secretory granules. After simultaneous selenium treatment, mercury is also found in nuclei of proximal tubule cells in the kidney and in macrophages. The "sulfide-osmium" method for ultrastructural localization of mercury suggested by Silberberg, Lawrence, and Leider (Arch Environ Health 19:7, 1969) and the light microscopic method using a photographic emulsion suggested by Umeda, Saito, and Saito (Jpn J Exp Med 39:17, 1969) have been experimentally analyzed and commented on.

Bioaccumulation of inorganic and methylated mercury by the gills of the shore crab Carcinus maenas: transepithelial fluxes and histochemical localization

“…The cytological resolution of the technique is highly valuable, but many limitations still remain. While the specificity of mercury detection seems beyond doubt (Danscher & Møller-Madsen 1985, Skak & Baatrup 1993, Braeckman & Raes 1999, all chemical forms of the metal could not be considered as reactive. If, as classically assumed, only sulfide-and selenide-bound metal atoms could act as catalysts for reduction of Ag + ions and deposition of silver grains, the histological detection should depend on the chemical fate of mercury after uptake.…”

“…Autometallography is a very sensitive technique for detection of sulfide-bound metal groups (Danscher 1984, Danscher & Møller-Madsen 1985, Newman & Jasani 1998, Braeckman & Raes 1999. These groups act as catalysts for reduction of Ag + ions to Ag atoms that themselves aggregate, allowing further catalysis, amplification of the reaction and deposition of easily detectable silver grains.…”

“…The routine of the method used in this work was based on that of Danscher & Møller-Madsen (1985) with further improvements (Baatrup & Doving 1990, Danscher et al 1994, Soto et al 1998). Sections for light or electron microscopy were incubated for exactly 1 h at a controlled temperature of 26 ± 0.2°C in complete darkness in a developer solution containing arabic gum (50%, Sigma), 0.1 M citrate buffer pH 7.9 (citric acid, Prolabo; sodium citrate, Sigma), 0.08 M hydroquinone (photographic grade, Sigma) and 3 mM silver lactate (lactic acid, silver salt, Sigma).…”

Localization of Inorganic and Organic Mercury in the Liver and Kidney of Cyprinus carpio by Autometallography

“…Critical target organs of mercury chloride trophic exposure are kidney, liver, blood, intestinal epithelium and lungs (Berlin & Ulberg, 1987;Nielsen & Andersen, 1989), whereas liver, nervous system, intestinal epithelium, kidney and muscle are common targets of organic mercury (Möller-Madsen & Danscher, 1991;Oliveira Ribeiro et al, 2002;Clarkson, 2003;Mela et al, 2007). Although chemical analyses provided information about tissue distribution, the exact cellular localization of mercury has not been available until the introduction of the autometallographic technique (AMG) (Danscher & Möller-Madsen, 1985;Baatrup & Danscher, 1987;Stoltenberg & Danscher, 2000). The AMG is an auto-induced silver amplification method of some metal atoms and metal molecules in biological sections by applying basic principles of photography (Danscher, 1984).…”

“…The AMG is an auto-induced silver amplification method of some metal atoms and metal molecules in biological sections by applying basic principles of photography (Danscher, 1984). Using AMG, metal atoms, metal sulphides or metals selenides can be visualized under the light and the electron microscopes after silver enhancement as black silver deposits (Danscher & Möller-Madsen, 1985;Mela et al, 2010).…”