Mercury chromosomal aberration

Krishnaja, A.P. and M.S. Rege. 1982. Induction of chromosomal aberrations in fish Boleophthalmus dussumieri after exposure in vivo to mitomycin C and heavy metals mercury, selenium and chromium. Mutat. Res. 102 71-82. 

Genetic and Neonatal Toxicity. The ability of heavy metals readily to cross the placenta and disrupt nucleic acids coupled with the high sensitivity of the fetus and neonate increases the potential dangers of congenital and neonatal toxicity. In mammalian leukocyte cultures, chromosomal aberrations have been reported with lead (112), arsenic (113), mercury (114), and methylmercury (115). Charbonneau, et al. (116) reported a lack of mutagenic effect for methylmercury. 

There is inconclusive evidence that occupational exposure to metallic mercury and to organic and inorganic mercury compounds, primarily through inhalation, causes structural and numerical chromosome aberrations in human lymphocytes. In one study, significant increases in the frequency of acentric fragments (chromosome breaks) occurred in 4 workers exposed to high concentrations of metallic mercury and in 18 workers exposed to a mixture of mercuric chloride, methylmercuric chloride,... 

Several studies were located regarding genotoxic effects in humans after oral exposure to organic mercury. A positive correlation between blood mercury levels and structural and numerical chromosome aberrations was found in the lymphocytes of 23 people who consumed mercury-contaminated fish (SkerfVing et al. 1974). However, several factors preclude acceptance of these findings as valid. With respect to the increased incidence of structural aberrations, smokers were not identified, it was unclear whether chromatid and chromosome gaps were excluded from the evaluation, and significant effects... 

In an in vitro study of the clastogenic effects of mercurials in animal cells, Howard et al. (1991) observed a dose-related increase in chromosome aberrations in Chinese hamster ovary (CHO) cells treated with... 

Popescu HI, Negru L, Lancranjan I. 1979. Chromosome aberrations induced by occupational exposure to mercury. Arch Environ Health 34 461-463. 

Akiyama M, Oshima H and Nakamura M (2001) Genotoxicity of mercury used in chromosome aberration test. Toxicol In Vitro 25 463-467. 

Significant sublethal effects of mercury include an increased frequency of cancers, birth defects, and chromosomal aberrations in laboratory animals and wildlife. Adverse sublethal effects of mercurials also include growth inhibition, abnormal reproduction, histopathology, high mercury accumulations and persistence, and disrupted biochemistry, metabolism, and behavior. These - and other aspects of exposure to various mercurials by living organisms - are documented and discussed for representative species of bacteria and other microorganisms, aquatic and terrestrial plants and invertebrates, fishes, amphibians, birds, and mammals. 

Metal ions and complexes may induce chromosome aberrations and Cu + and Pb + (Levan, 1945) or phenyl and methyl mercury (Ramel, 1969) very efficiently lead to disturbances of the nuclear spindle which are of a kind that could lead to aneuploidy. Diploids are less suited to detect the phenotypic effect in Xg of chromosome losses. However, a certain mutagenic effect in the pea caused by a number of metal ions was fpund by von Rosen (1964). Sterility at doses above LD50 of the mercury complexes has been recorded in barley (Ehrenberg et aLy unpublished). Scheibe (1959) found a mutagenic effect in barley and wheat of AICI3 when applied to the spike following the method of Oehlkers (1949). 

Inorganic and organic mercury compounds are generally not considered to be carcinogenic in humans [61,62]. There are some reports on chromosomal aberrations caused by mercury vapor [63] or methylmercury [64], but these effects are negligible in comparison to other negative effects of mercury [2,14]. 

Hg(II) induced SCEs only slightly in CHO cells but a greater response was seen in human lymphocytes (Howard et al. 1991 Morimoto et al. 1982). Chromosomal aberrations have been induced by Hg(II) and by organomercury compounds in a variety of cells (Leonard et al. 1983 Howard et al. 1991). In addition to its clastogenic effects, mercury compounds cause a disturbance of mitosis due to their reactions with the sulfhydryl groups in the spindle fiber proteins. Deleterious effects on the spindle apparatus were seen with Me-Hg-Cl in a number of studies (Watanabe et al. 1982 Curle et al. 1987). Effects on the spindle apparatus are likely to lead to errors of chromosomal segregation (i.e., aneuploidy) (Ramel and Magnusson 1979 Verschaeve et al. 1984). 

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