Metabolism of tellurium, antimony and germanium simultaneously administered to rats

Abstract

-Recently, tellurium (Te), antimony (Sb) and germanium (Ge) have been used as an alloy in phase-change optical magnetic disks, such as digital versatile disk-random access memory (DVD-RAM) and DVD-recordable disk (DVD-RW). Although these metalloids, the so-called "exotic" elements, are known to be non-essential and harmful, little is known about their toxic effects and metabolism. Metalloid compounds, tellurite, antimonite and germanium dioxide, were simultaneously administered to rats. red blood cells (RBCs): Te accumulated in RBCs in the dimethylated form, while Sb accumulated in the inorganic/non-methylated form. In addition, trimethyltelluronium (TMTe) was the urinary metabolite of Te, whereas Sb in urine was not methylated but oxidized. Ge was also not methylated in rats. These results suggest that each metalloid is metabolized via a unique pathway.

Toxicometallomics for Research on the Toxicology of Exotic Metalloids Based on Speciation Studies

“…22,51 The accumulation in RBCs was also observed when Te or arsenic was ingested. As mentioned above, the accumulated species of Te and arsenic were the dimethylated forms.…”

“…21 The gel filtration column is able to separate antimony(V) citrate from free Sb(V) ions in urine. 22 Other chromatographic mechanisms, such as multi-mode gel filtration and cation-exchange chromatography, are also effective to separate organic Te metabolites. 23 As mentioned above, the advantage of utilizing a gel filtration column is that the separation conditions are similar to the physiological conditions.…”

“…Accumulated Sb in rat RBCs was specifically bound to hemoglobin-like DMAs and dimethylated Te. 22 To specify the chemical form of Sb bound to hemoglobin, Sb was cleaved off from hemoglobin with hydrogen peroxide, and then the cleaved Sb species was subjected to HPLC-ICP-MS. The cleaved Sb compound showed the same chromatographic behavior as that of antimonate, 22 suggesting that the Sb that specifically bound to hemoglobin was an inorganic form, not a methylated form.…”

Advances in Effect of Germanium or Germanium Compounds on Animals—A Review

“…Animal experimental results showed that germanium compounds, both inorganic and organic, are rapidly and almost completely absorbed into the lungs and gastrointestinal tract mucosa [2] [4]. The germanium and plasma proteins can be transported in an unbound state if they are injected into the blood directly, and are excreted by both the kidney and the gastrointestinal tract, where the kidney is the chief excretory organ (80% versus 13%) [5] [6] [7]. Chart 1.…”

“…Germanium enters the organism and binds to hemoglobin, thereby ensuring normal cellular aerobic metabolism [46]. In addition, the germanium compounds can capture the hydrogen ions and other harmful ions in the metabolites, and play a role in purifying blood at different degrees [47].…”