Identification of urinary tellurium metabolite in rats administered sodium tellurite

Abstract

Tellurium (Te) is one of the important metalloids used in industry, and is ubiquitously found in the environment. However, the biological and toxicological effects of Te are still unclear despite its being recognized as a hazardous element. In this study, we attempted to identify urinary Te metabolites (UTMs) in rats by HPLC-ICP-MS and electrospray ionization (ESI)-MS. To unambiguously identify UTMs, two different chromatographic mechanisms, i.e., multi-mode gel filtration and cation exchange columns, were employed. The major UTM detected after ingestion of tellurite was trimethyltelluronium, and no urinary sugar metabolites containing Te were detected despite the fact that the major urinary selenometabolite was a selenosugar (methyl-2acetamido-2-deoxy-1-seleno-b-D-galactopyranoside). Interestingly, the ingestion of tellurite enhanced the excretion of selenometabolites in urine. These results suggest that Te is discretely metabolized from selenium (Se), an essential element belonging to the same group, although it affects the metabolism of Se in rats. Thus, the disturbance of Se metabolism, i.e., the induction of Se deficiency, may be one of the potential toxic effects of Te.

Speciation of inorganic tellurium from seawater by ICP‐MS following magnetic SPE separation and preconcentration

“…the literature for speciation of tellurium is shown in Table 4. As could be seen, the LODs of this method are much lower than those obtained by SPE-HG-AAS [32], SPE-ICP-MS [12], SPE-ICP-AFS [9], LLE-AAS [1], CE-UV [33], and HPLC-ICP-MS [4].…”

“…Recently, Te, as an alloy with germanium (Ge) and antimony (Sb), has found use in digital versatile disk-random access memory (DVD-RAM) and DVDrecordable disks (DVD-RW) [1]. Thus, these metalloids are expected to be widely used in everyday life as storage media.…”

Metabolism of tellurium, antimony and germanium simultaneously administered to rats

“…Te was preferably distributed to the lungs and spleen. It is reported that Te was metabolized by methylation, and the resulting TMTe was excreted into urine (Ogra et al, 2007). As a metabolic intermediate, volatile dimethyltelluride could be formed and the lungs seemed to accumulate the volatile metabolite (DeMeio and Jetter, 1948).…”

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

“…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. In addition, the column does not require the addition of chelators, such as EDTA, tartaric acid, and phthalic acid, to achieve good separation of Te and Sb species in biological matrices.…”

“…[41][42][43] Recently, the major urinary Te metabolite in rat, an experimental animal, was identified by HPLC-ICP-MS and ESI-MS-MS after tellurite, an inorganic Te compound, was ingested. 23 The Te metabolite was trimethyltelluronium (TMTe). However, no peaks corresponding to Te-containing sugars, i.e., tellurosugars, were detected on HPLC-ICP-MS equipped with a gel filtration column or a cation-exchange column.…”