Linked Life Data

16918239

Source:http://linkedlifedata.com/resource/pubmed/id/16918239

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2006-8-21
pubmed:abstractText
Inorganic arsenic is converted to methylated metabolites, and most is excreted in urine as dimethylarsinic acid in humans and animals. The present study was conducted to investigate the metabolism of arsenic and identify hepatic and renal metabolites of arsenic after an intravenous injection of arsenite (0.5 mg As/kg body weight) in rats. Similar levels of arsenic were found in the soluble (SUP) and nonsoluble sediment (SED) fractions of both organs after 1 h. More than 80% of the SUP arsenic was bound to high molecular weight (HMW) proteins in both organs. Arsenic bound to the HMW and SED proteins were oxidized with H(2)O(2) and released in the pentavalent forms (arsenate, monomethylarsonic, and dimethylarsinic acids). The relative ratios of the three arsenicals changed depending on organ, fraction (HMW and SED), and time. Since the arsenic metabolites/intermediates were liberated from proteins by oxidation with H(2)O(2) and recovered in the pentavalent forms, and only tri- but not pentavalent arsenicals were bound to proteins in vitro, it was deduced that arsenic metabolites bound to proteins during the successive methylation pathway are in the trivalent forms; that is, successive methylation reaction takes place with simultaneous reductive rather than stepwise oxidative methylation. Thus, on the basis of the present observations, it was proposed that inorganic arsenic was successively methylated reductively in the presence of glutathione, rather than a stepwise oxidative methylation, and pentavalent arsenicals (MMA(V) and DMA(V)) were present as end products of metabolism, rather than intermediates. We also discussed the in vitro formation of dimethylthioarsenicals after incubating dimethylarsinous acid with liver homogenate.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0893-228X
pubmed:author
pubmed:issnType
Print
pubmed:volume
19
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1010-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Trivalent arsenicals are bound to proteins during reductive methylation.
pubmed:affiliation
Graduate School of Pharmaceutical Sciences, Chiba University, Chuo, Chiba 260-8675, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't