Metals hepatic accumulation

After induction of MT synthesis, the hepatic accumulation of inorganic mercury is also increased in rats. While both hepatic and renal accumulation of inorganic mercury and hepatic zinc content increased in association with zinc pretreatment, the urinary and fecal excretions of mercury were decreased (Zalups and Cherian 1992). These results support an intracellular metal-binding role for preinduced MT in the liver and kidney. The... 

The above and other transporters involved in the uptake of essential metal cations for animals are subject to extensive regulation [71]. The regulatory mechanisms can be sophisticated and they can involve networks of essential and toxic metals as recently demonstrated and reviewed [7,70,72]. Since increased hepatic accumulation of ingested cadmium is associated with upregulation of several intestinal transporters in mice fed diets deficient in essential metals, it follows that Cd " entry into cells, and its intestinal absorption in particular, strongly depends on the status of the animal or human with respect to these essential metals. 

Artificial liver support systems aim at the extracorporeal removal of water soluble and protein-bound toxins (albumin being the preferential binding protein) associated with hepatic failure. Albumin contains reversible binding sites for substances such as fatty acids, hormones, enzymes, dyes, trace metals and drugs [26] and therefore helps elimination by kidneys of substances that are toxic in the unbound state. It should be noticed that the range of substances to be removed is broad and not completely identified. Clinical studies showed that the critical issue of the clinical syndrome in liver failure is the accumulation of toxins not cleared by the failing liver. Based on this hypothesis, the removal of lipophilic, albumin-bound substances, such as bilirubin, bile adds, metabolites of aromatic amino acids, medium-chain fatty acids, and cytokines, should be benefidal to the dinical course of a patient in liver failure. 

Cyclosporine-induced nephropathy was reduced by administration of Chinese salvia extract to rats (Peng et al. 2006 Qiao et al. 2001). Extracts of Chinese salvia attenuated adriamycin-induced cardiac and hepatic toxicity in healthy rats (You et al. 2007) and vanadium-induced gastrointestinal stress and metal accumulation in diabetic rats (Zhang etal.2008). 

Biliary excretion is the only mechanism for copper elimination, and the amount of copper excreted in the bile is direcMly proportional to the size of the hepatic copper pcx)l. Becanse hepatic nptake of dietary copper in not saturable, hepatic copper accumulation can easily be induced. Toxicity of copper, however, depends on its molecailar asscx iation and subcellular Icxnhzation rather than on its concentration in the Uver. MetaUothionein-bound copper is nontoxic. Several metals including zinc crtn induce metaUothionein synthesis. 

The hepatic tissue and pectoral muscle of a great cormorant P. carbo) specimen caught in July 1999 at river profile Banatska Palanka - Ram was also analyzed. Cormorant, as an ichthyophagous bird represents an extranely suitable object for indirect determination of heavy metals and specific organic pollutant accumulation in fish. The hepatic tissue contained much higher concentrations of copper, mercury, PAHs and PCBs than the muscles (Table 2). It is important to emphasize that this was the first record of PCB presence in the tissues of an ichthyophagous bird although this kind of the study had been performed over many years [1,2]. 

Copper is detectable histochemically using rubianic acid, which reacts with the metal to yield a black precipitate. Such techniques have shown that the copper accumulates in the hepatic cell first leaving the Kupffer cell free of copper. In the hepatic cell, at first the metal is diffused throughout the cytoplasm, but later it accumulates to form a metallic halo around the nucleus. Copper accumulation in the liver cell precedes the development of cirrhosis. The copper is widely distributed among the brain cells, but the largest concentration of metal is usually found in the basal ganglia. The type of nerve cell involved in copper accumulation in Wilson s disease has not been unequivocally identified. 

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