RESUMEN
The objective of this study was to investigate whether quantum dot 705 (QD705) disrupts the cellular antioxidant systems leading to hepatotoxicity in mice. Mice were intravenously injected with QD705 and then sacrificed at week 12 or 16. Homeostasis of antioxidant-related metals, antioxidant activities, induction of oxidative stress, and toxicity in the liver were investigated. Although no histopathological change was observed, a time- and dose-dependent increase in metallothionein expression and reduction in liver function was noticed. Increased copper, zinc, and selenium levels and enhancements of the trace metal-corresponding transporters were noted at week 12. At week 16, a decline of selenium from its elevated level at week 12 was observed, which was accompanied by changes in glutathione peroxidase activity as well as in redox status. A significant reduction in superoxide dismutase activity was observed at 16 weeks. Furthermore, a corresponding elevation of heme oxygenase-1 expression, 8-oxo-7,8-dihydro-2'-deoxyguanosine, interleukin-6 and tumor necrosis factor-alpha suggested the presence of oxidative stress, oxidative DNA damage and inflammation.
Asunto(s)
Cadmio/química , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Puntos Cuánticos , Selenio/química , Telurio/química , Animales , Cadmio/toxicidad , Proteínas de Transporte de Catión/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Citocinas/metabolismo , Expresión Génica/efectos de los fármacos , Inmunohistoquímica , Hígado/química , Hígado/metabolismo , Hígado/patología , Masculino , Metalotioneína/metabolismo , Ratones , Ratones Endogámicos ICR , Estrés Oxidativo/efectos de los fármacos , Selenio/toxicidad , Superóxido Dismutasa/metabolismo , Telurio/toxicidadRESUMEN
The objective of this study was to assess individual variation in inorganic arsenic methylation capability and the association between selenium levels in urine and blood, and inorganic arsenic methylation capability among residents of the Lanyang Basin who drank groundwater and were exposed to high concentrations of inorganic arsenic. According to the arsenic concentration of their drinking water, they were equally and randomly classified into four groups of 252 persons. It turned out that the higher the concentration of arsenic in well water was and thus the cumulative arsenic exposure, the higher the total inorganic arsenic metabolites in urine (total As(i)) and the overall inorganic and organic arsenic in urine (overall As(i+o)) were. The percentage of inorganic arsenic significantly decreased and the DMA percentage significantly increased as the concentration of urinary selenium and serum alpha-tocopherol increased. It appeared that urinary selenium levels increased the metabolism by methylation of arsenic, a finding that requires further investigation.