Mercury in liver

Sundlof SF, Spaulding MG, Wentworth JD, Steible CK. 1994. Mercury in livers of wading birds (Ciconiiformes) in Southern Florida. Arch Environ Contam Toxicol 27 299-305. 

Hurtado-Banda R, Gomez-Alvarez A, Marquez-Fan as JF, Cordoba-Figueroa M, Navano-Garda G, Medina-Judrez LA (2012) Total mercury in liver and muscle tissue of two coastal sharks from the northwest of Mexico. Bull Environ Contam Toxicol 88(6) 971-975... 

Liver is 1 of the tissues most frequently analyzed for contaminant residne in wildlife, but maybe 1 of the least useful because of the poor correlation between fiver mercniy concentration and effects, and because of the tendency of the liver to accumulate mercury over time (Stewart et al. 1999 Scheuhammer et al. 2001). Liver is a major site of demethylation therefore, the proportion of fiver mercury present as MeHg is not representative of exposure to MeHg. Moreover, most mercury in fiver is botmd to metallothionein or other suUydryl-bearing proteins, which immobilize it (Med-insky and Klaassen 1996 Yasutake etal. 1997 Aschner 1999). Therefore, fiver mercury residue values must be used with caution, and only when more suitable tissues are unavailable. 

Weech SA, Wilson LK, Langelier KM, Elliott JE. 2003. Mercury residues in livers of bald eagles Haliaeetus leucocephalus) found dead or dying in British Columbia, Canada (1987-1994). Arch Environ Contam Toxicol 45 562-569. 

Evidence suggests that lead exacerbates the toxic effects of mercury. In the rat, the administration of lead nitrate increased kidney and liver glutathione content and resulted in increased mercury deposition in the kidney, along with increased lethality in rats (Congiu et al. 1979). 

A battery of different biochemical quantitative assays was applied to many different tissues and species. DNA damage and lipid peroxidation assays measure the direct impact of genotoxics and oxidant pollutants [16,17] whereas alteration of GSH levels in liver is a marker for oxidative stress [18]. Mercury and other heavy metals are known to induce metallothionein levels in different tissues although this effect is variable in different species and organs [19-22]. 

This area was the most profusely studied in the AQUATERRA project in terms of biological effects in fish populations. Barbel and bleak were the sentinel species selected in this area and an array of histological and biochemical tests were used to monitor the impact due to three major sources of pollution mercury and OCs at Monzon (with a comparison in one of the papers with Flix) and PBDEs in Barbastro [1—4, 37]. Mercury pollution was directly correlated to an increase of MTprotein in the liver of barbel captured downstream Monzon when compared to samples captured upstream (Fig. 3a). However, mRNA quantitative analyses failed to show any differences between downstream and upstream Monzon, neither correlated with MT protein levels. Further studies showed that MT mRNA in liver is a rather weak marker for chronic metal pollution in liver (see below) [4], The presence of degenerative hepatocytes in barbels and bleaks was also linked to mercury poisoning although it can also reflect the impact by other pollutants, like OCs or PBDEs (Fig. 3e). 

Mercury concentrations in livers of four species of pinniped mammals... 

Figure 5.2 Mercury concentrations in livers of tour species of pinniped mammals. (From Eisler, R. 1984. Trace metal changes associated with age of marine vertebrates. Biol. Trace Elem. Res. 6 165-180. With permission.)... 

Barghigiani, C., D. Pellegrini, and E. Carpene. 1989. Mercury binding proteins in liver and muscle of flat fish from the northern Tyrrhenian Sea. Comp. Biochem. Physiol. 94C 309-312. 

Eaton, R.D.P., D.C. Secord, and P. Hewitt. 1980. An experimental assessment of the toxic potential of mercury in ringed-seal liver for adult laboratory cats. Toxicol. Appl. Pharmacol. 55 514-521. 

Goldstein, R.M., M.E. Brigham, and J.C. Stauffer. 1996. Comparison of mercury concentrations in liver, muscle, whole bodies, and composites of fish from the Red River of the North. Canad. Jour. Fish. Aquat. Sci. 53 244-252. 

Sellinger, M., N. Ballatori, and J.L. Boyer. 1991. Mechanism of mercurial inhibition of sodium-coupled alanine uptake in liver plasma membrane vesicles from Raja erinacea. Toxicol. Appl. Pharmacol. 107 369-376. 

Nielsen, C.O. and R. Dietz. 1990. Distributional pattern of zinc, cadmium, mercury, and selenium in livers of hooded seal (Cystophora cristata). Biol. Trace Elem. Res. 24 61-71. 

Concentrations of V, Mn, Fe, Cr, Co, Cu, Zn, As, Se, Mo, Ag, Cd, Tl, Hg, Pb, and organic mercury (Org-Hg) were determined in liver, kidney, and muscle of healthy Caspian seals (Phoca caspica) collected in 1998. These concentrations were compared with those of seals infected with canine distemper virus (CDV) found stranded along the coastal areas in 2000 (Table 1). Concentrations of toxic elements (As, Ag, Cd, Tl, Hg, Pb, and Org-Hg) in Caspian seals stranded in 2000 were comparable or lower than those of samples collected in 1998 and in other pinnipeds. Thus it may be inferred that these elements were not the causative agents in the deaths of the seals. In contrast, concentrations of Zn and Fe were much higher in diseased Caspian seals than those in other pinnipeds. Zinc concentrations in all tissues of Caspian seals also increased during 1993-2000. Furthermore, negative correlations were found between blubber thickness and hepatic and renal Zn concentrations. These results imply the disturbance... 

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