Linked Life Data

17988700

Source:http://linkedlifedata.com/resource/pubmed/id/17988700

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2007-12-25
pubmed:abstractText
All nutritional selenium sources are transformed into the assumed common intermediate selenide for the syntheses of selenoproteins for utilization and/or of selenosugar for excretion. Methylselenol [monomethylselenide, MMSe] is the assumed intermediate leading to other methylated metabolites, dimethylselenide (DMSe) and trimethylselenonium (TMSe) for excretion, and also to the intermediate selenide from methylselenocysteine and methylseleninic acid (MSA). Here, related methylation and demethylation reactions were studied in vitro by providing chemically reactive starting substrates (76Se-selenide, 77Se-MMSe and 82Se-DMSe) which were prepared in situ by the reduction of the corresponding labeled proximate precursors (76Se-selenite, 77Se-MSA and 82Se-dimethylselenoxide (DMSeO), respectively) with glutathione, the three substrates being incubated simultaneously in rat organ supernatants and homogenates. The resulting chemically labile reaction products were detected simultaneously by speciation analysis with HPLC-ICP-MS after converting the products and un-reacted substrates to the corresponding oxidized derivatives (selenite, MSA and DMSeO). The time-related changes in selenium isotope profiles showed that demethylation of MMSe to selenide was efficient but that of DMSe to MMSe was negligible, whereas methylation of selenide to MMSe, and MMSe to DMSe were efficient, and that of DMSe to TMSe occurred less efficiently. The present methylation and demethylation reactions on equilibrium between selenide, MMSe and DMSe without producing selenosugar and selenoproteins indicated that DMSe rather than TMSe is produced as the end product, suggesting that DMSe is to be excreted more abundantly than TMSe. Organ-dependent differences in the methylation and demethylation reactions were characterized for the liver, kidney and lung.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Glutathione, http://linkedlifedata.com/resource/pubmed/chemical/Isotopes, http://linkedlifedata.com/resource/pubmed/chemical/Methanol, http://linkedlifedata.com/resource/pubmed/chemical/Organoselenium Compounds, http://linkedlifedata.com/resource/pubmed/chemical/Oxides, http://linkedlifedata.com/resource/pubmed/chemical/Selenious Acid, http://linkedlifedata.com/resource/pubmed/chemical/Selenium, http://linkedlifedata.com/resource/pubmed/chemical/Selenium Compounds, http://linkedlifedata.com/resource/pubmed/chemical/dimethylselenide, http://linkedlifedata.com/resource/pubmed/chemical/dimethylselenoxide, http://linkedlifedata.com/resource/pubmed/chemical/hydrogen selenide, http://linkedlifedata.com/resource/pubmed/chemical/methaneselenol, http://linkedlifedata.com/resource/pubmed/chemical/methylselenic acid
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0041-008X
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
226
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
169-77
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Methylation and demethylation of intermediates selenide and methylselenol in the metabolism of selenium.
pubmed:affiliation
Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo, Chiba 260-8675, Japan.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't