Histochemical demonstration of mercury in the olfactory system of salmon (Salmo salar L. ) following treatments with dietary methylmercuric chloride and dissolved mercuric chloride

Journal Article · Sat Dec 01 00:00:00 EST 1990 · Ecotoxicology and Environmental Safety; (USA)

DOI:https://doi.org/10.1016/0147-6513(90)90007-R· OSTI ID:5735003

Baatrup, E; Doving, K B ^[1]

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1. Univ. of Aarhus, (Denmark)

The deposition of organic and inorganic mercury compounds was studied histochemically in the salmon (Salmo salar L.) olfactory system. One group of salmon was given fodder pellets containing methylmercuric chloride (CH{sub 3}HgCl, 99 micrograms Hg/g) for 4 weeks. Other groups of fish were exposed to dissolved mercuric chloride (HgCl{sub 2}, 270 micrograms Hg/liter) for 2, 6, and 12 hr, respectively. In both series of experiments, the radioisotope {sup 203}Hg was included in order to determine the accumulation of mercury in the olfactory system. Gamma-spectrometry showed that both mercury compounds accumulated in the olfactory rosettes and their nerves. Tissue sections from the rosettes and olfactory nerves were subjected to autometallographic silver enhancement, thereby rendering mercury deposits visible for light and electron microscopy. Microscopic analysis demonstrated an intense and comprehensive Hg deposition in the axons and Schwann cells of both methylmercury- and inorganic mercury-exposed fish. On the other hand, the two mercury compounds showed different staining patterns in the sensory epithelium. The silver grains evoked by methylmercury were localized predominantly in lysosome-like inclusions within the receptor cells, while those produced by HgCl{sub 2} exposure were situated mainly along the borders of neighboring cells. The present findings that organic and inorganic mercury compounds were deposited in the olfactory system along its whole length, from the receptor cell apices to the brain, support the electrophysiological results presented elsewhere.

• OSTI ID: 5735003
• Journal Information: Ecotoxicology and Environmental Safety; (USA), Vol. 20:3; ISSN 0147-6513
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
59 BASIC BIOLOGICAL SCIENCES
MERCURY
TISSUE DISTRIBUTION
METHYLMERCURY
OLFACTORY BULBS
SENSITIVITY
SALMON
CONTAMINATION
MERCURY 203
METABOLISM
TRACER TECHNIQUES
ANADROMOUS FISHES
ANIMALS
AQUATIC ORGANISMS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
BRAIN
CENTRAL NERVOUS SYSTEM
DAYS LIVING RADIOISOTOPES
DISTRIBUTION
ELEMENTS
EVEN-ODD NUCLEI
FISHES
HEAVY NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
MERCURY COMPOUNDS
MERCURY ISOTOPES
METALS
NERVOUS SYSTEM
NUCLEI
ORGANIC COMPOUNDS
ORGANIC MERCURY COMPOUNDS
ORGANS
RADIOISOTOPES
VERTEBRATES
560300* - Chemicals Metabolism & Toxicology
550501 - Metabolism- Tracer Techniques