Effects of endogenous and exogenous thiols on the distribution of mercurial compounds in mouse tissues

Aihara, M; Sharma, Raghubir P.

doi:10.1007/bf01054909

Cited by 9 publications

(4 citation statements)

References 29 publications

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“…In blood, MeHg distributes 90% to red blood cells and 10% to plasma. Inorganic Hg distributes approximately evenly or with a cell: plasma ratio of ⩾2 [55]. O'Connor and Nielsen [5] found that length of exposure was a better predictor of tissue residue level than dose in otters, but that higher doses produced an earlier onset of clinical signs.…”

Section: Mammalsmentioning

confidence: 99%

Effects of mercury on wildlife: A comprehensive review

Wolfe

Schwarzbach

Sulaiman³

1998

Enviro Toxic and Chemistry

750

417

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Abstract-Wildlife may be exposed to mercury (Hg) and methylmercury (MeHg) from a variety of environmental sources, including mine tailings, industrial effluent, agricultural drainwater, impoundments, and atmospheric deposition from electric power generation. Terrestrial and aquatic wildlife may be at risk from exposure to waterborne Hg and MeHg. The transformation of inorganic Hg by anaerobic sediment microorganisms in the water column produces MeHg, which bioaccumulates at successive trophic levels in the food chain. If high trophic level feeders, such as piscivorous birds and mammals, ingest sufficient MeHg in prey and drinking water, Hg toxicoses, including damage to nervous, excretory and reproductive systems, result. Currently accepted no observed adverse effect levels (NOAELs) for waterborne Hg in wildlife have been developed from the piscivorous model in which most dietary Hg is in the methyl form. Such model are not applicable to omnivores, insectivores, and other potentially affected groups, and have not incorpotated data from other important matrices, such as eggs and muscle. The purpose of this paper is to present a comprehensive review of the Hg literature as it relates to effects on wildlife, including previously understudied groups. We present a critique of the current state of knowledge about effects of Hg on wildlife as an aid to identifying missing information and to planning research needed for conducting a complete assessment of Hg risks to wildlife. This review summarizes the toxicity of Hg to birds and mammals, the mechanisms of Hg toxicity, the measurement of Hg in biota, and interpretation of residue data.

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Section: Mammalsmentioning

confidence: 99%

Effects of mercury on wildlife: A comprehensive review

Wolfe

Schwarzbach

Sulaiman³

1998

Enviro Toxic and Chemistry

750

417

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“…GSH directly sequesters Hg 2+ through the sulfhydryl group of the cysteine moiety. Reduced GSH and other small molecules having a thiol group such as cysteine, homocysteine, and N-acetyl cysteine contribute to the Hg excretion from the cell and the body in the form of a thiol conjugate. , In addition, reduced GSH interacts with free radicals to reduce the oxidative stress induced by Hg 2+ . , The GSH conjugate of MeHg is the primary chemical form to be excreted into the bile and transported to the kidney. , Thus, GSH plays multiple roles and is responsible for the detoxification of both Hg 2+ and MeHg.…”

Section: Introductionmentioning

confidence: 99%

“…13 The GSH conjugate of MeHg is the primary chemical form to be excreted into the bile and transported to the kidney. 15,16 Thus, GSH plays multiple roles and is responsible for the detoxification of both Hg 2+ and MeHg.…”

Section: ■ Introductionmentioning

confidence: 99%

Formation Mechanism and Toxicological Significance of Biogenic Mercury Selenide Nanoparticles in Human Hepatoma HepG2 Cells

Tanaka

Usuzawa

Yoshida

et al. 2021

Chem. Res. Toxicol.

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It is widely recognized that the toxicity of mercury (Hg) is attenuated by the simultaneous administration of selenium (Se) compounds in various organisms. In this study, we revealed the mechanisms underlying the antagonistic effect of sodium selenite (Na 2 SeO 3 ) on inorganic Hg (Hg 2+ ) toxicity in human hepatoma HepG2 cells. Observations by transmission electron microscopy indicated that HgSe (tiemannite) granules of up to 100 nm in diameter were accumulated in lysosomal-like structures in the cells. The HgSe granules were composed of a number of HgSe nanoparticles, each measuring less than 10 nm in diameter. No accumulation of HgSe nanoparticles in lysosomes was observed in the cells exposed to chemically synthesized HgSe nanoparticles. This suggests that intracellular HgSe nanoparticles were biologically generated from Na 2 SeO 3 and Hg 2+ ions transported into the cells and were not derived from HgSe nanoparticles formed in the extracellular fluid. Approximately 85% of biogenic HgSe remained in the cells at 72 h post culturing, indicating that biogenic HgSe was hardly excreted from the cells. Moreover, the cytotoxicity of Hg 2+ was ameliorated by the simultaneous exposure to Na 2 SeO 3 even before the formation of insoluble HgSe nanoparticles. Our data confirmed for the first time that HepG2 cells can circumvent the toxicity of Hg 2+ through the direct interaction of Hg 2+ with a reduced form of Se (selenide) to form HgSe nanoparticles via a Hg−Se soluble complex in the cells. Biogenic HgSe nanoparticles are considered the ultimate metabolite in the Hg detoxification process.

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“…Importantly, we found that the vast majority of Hg in blood was associated with the cellular fraction rather than with plasma (Table 3). In mammals, 90% of blood Hg is found in RBCs and 10% in plasma (Aihara and Sharma 1986;Wolfe et al 1998). We found, on average, 2.5%-8.8% of blood Hg in plasma (Table 3).…”

Section: Discussionmentioning

confidence: 99%

Mercury concentrations in multiple tissues of Arctic Iceland Gulls (Larus glaucoides) wintering in Newfoundland

Bond

Robertson

2015

Arctic Science

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Anthropogenic mercury (Hg) emissions are increasing and are potentially of concern for Arctic-nesting seabirds, particularly those that spend part of their year near dense human habitation. Iceland Gulls (Larus glaucoides B. Meyer, 1822) breed in the eastern Canadian Arctic and spend the majority of winter in towns and cities in eastern Newfoundland. We measured Hg in breast feathers, blood plasma, and red blood cells of Iceland Gulls wintering in and around St. John's, Newfoundland and Labrador, from 2011 to 2014. Mercury in blood plasma comprised <10% of the total blood Hg. We found no difference in red blood cell Hg between first-winter and adult birds, which likely reflects their similar feeding habits. Feather Hg in adults was significantly greater than that in first-winter birds because adults had accumulated a greater body Hg burden to excrete (up to a year, compared with a few months' accumulation in first-winter birds). Overall, concentrations were among the lowest found for Larus spp. and Arctic gulls, suggesting that Hg does not pose a risk to Iceland Gulls at the present.

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Effects of endogenous and exogenous thiols on the distribution of mercurial compounds in mouse tissues

Cited by 9 publications

References 29 publications

Effects of mercury on wildlife: A comprehensive review

Effects of mercury on wildlife: A comprehensive review

Formation Mechanism and Toxicological Significance of Biogenic Mercury Selenide Nanoparticles in Human Hepatoma HepG2 Cells

Mercury concentrations in multiple tissues of Arctic Iceland Gulls (Larus glaucoides) wintering in Newfoundland

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