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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

A systematic study of the disposition and metabolism of mercury species in mice after exposure to low levels of thimerosal (ethylmercury)

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Autor(es):
Hornos Carneiro, Maria Fernanda [1] ; Oliveira Souza, Juliana Maria [1] ; Grotto, Denise [1, 2] ; Batista, Bruno Lemos [1, 3] ; de Oliveira Souza, Vanessa Cristina [1] ; Barbosa, Jr., Fernando [1]
Número total de Autores: 6
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, Fac Ciencias Farmaceut Ribeirao Preto, Lab Toxicol & Essencialidade Metais, BR-14040903 Ribeirao Preto, SP - Brazil
[2] Univ Sorocaba, Programa Posgrad Ciencias Farmaceut, BR-18023000 Sorocaba, SP - Brazil
[3] Univ Fed ABC, Ctr Ciencias Nat & Humanas, BR-0910170 Santo Andre, SP - Brazil
Número total de Afiliações: 3
Tipo de documento: Artigo Científico
Fonte: Environmental Research; v. 134, n. SI, p. 218-227, OCT 2014.
Citações Web of Science: 17
Resumo

Thimerosal (TM) is an ethylmercury (etHg)-containing preservative used in some vaccines despite very limited knowledge on the kinetics and direct interaction/effects in mammals' tissues after exposure. Thus, this study aimed to evaluate the kinetics of Hg species in mice in a time course analysis after intramuscular injection of TM, by estimating Hg half-lives in blood and tissues. Mice were exposed to one single intramuscular dose of 20 mu g of Hg as TM. Blood, brain, heart, kidney and liver were collected at 0.5 hour (h), 1 h, 8 h, 16 h, 144 h, 720 h and 1980 h after TM exposure (n=4). Hg species in animal tissues were identified and quantified by speciation analysis via liquid chromatography hyphenated with inductively coupled mass spectrometry (LC-ICP-MS). It was found that the transport of etHg from muscle to tissues and its conversion to inorganic Hg (inoHg) occur rapidly. Moreover, the conversion extent is modulated in part by the partitioning between EtHg in plasma and in whole blood, since etHg is rapidly converted in red cells but not in a plasma compartment Furthermore, the dealkylation mechanism in red cells appears to be mediated by the Fenton reaction (hydroxyl radical formation). Interestingly, after 0.5 h of TM exposure, the highest levels of both etHg and inoHg were found in kidneys (accounting for more than 70% of the total Hg in the animal body), whereas the brain contributed least to the Hg body burden (accounts for < 1.0% of total body Hg). Thirty days after TM exposure, most Hg had been excreted while the liver presented the majority of the remaining Hg. Estimated half-lives (in days) were 8.8 for blood, 10.7 for brain, 7.8 for heart, 7.7 for liver and 45.2 for kidney. Taken together, our findings demonstrated that TM (etHg) kinetics more closely approximates Hg2+ than methylmercury (meHg) while the kidney must be considered a potential target for etHg toxicity. (C) 2014 Elsevier Inc. All rights reserved. (AU)

Processo FAPESP: 11/08467-0 - A especiação química como ferramenta para a identificação e quantificação de espécies de Hg e As em diferentes amostras biológicas visando a segurança alimentar e a elucidação da toxicocinética do timerosal
Beneficiário:Fernando Barbosa Júnior
Linha de fomento: Auxílio à Pesquisa - Regular