Preferential organ distribution of methylselenol source Se-methylselenocysteine relative to methylseleninic acid
- Graduate School of Pharmaceutical Sciences, Chiba University, Chuo, Chiba 260-8675 (Japan)
It has been proposed that Se-methylselenocysteine (MeSeCys) and methylseleninic acid (MSA{sup IV}) are efficiently transformed through the {beta}-lyase and reduction reactions, respectively, into methylselenol, the assumed biologically active selenometabolite responsive for the anti-carcinogenicity and anti-oxidant actions of selenium. The bioavailability and distribution of the two selenium sources in major organs/tissues were compared under exactly identical conditions. Namely, labeled selenium sources {sup 76}Se-MeSeCys and {sup 77}Se-MSA{sup IV}, at a single oral dose of 10 {mu}g Se/kg body weight each, were administered simultaneously to rats that had been depleted of natural abundance selenium with a single isotope {sup 78}Se. The same dose of {sup 82}Se-selenite was also administered as a reference selenium source. The distributions of the three labeled selenium isotopes were determined 3 h after the administration in 13 organs/tissues/blood. MeSeCys was taken up more efficiently by most organs, especially the pancreas and duodenum, than MSA{sup IV} and selenite, the latter two sources being taken up similarly to each other except for in the kidney, liver, and spleen, where the three labeled isotopes were detected at comparable concentrations. The labeled selenium in the liver supernatant was speciated by HPLC inductively coupled argon plasma-mass spectrometry (ICP-MS), and it was suggested that MeSeCys was delivered in its intact form to organs, and then transformed into methylselenol. In addition to the known properties of that MeSeCys is chemically more stable than MSA{sup IV} and is a naturally occurring edible product, and that MeSeCys produces methylselenol much more efficiently than a homologous selenoamino acid selenomethionine, the present study revealed that MeSeCys is more efficiently distributed than MSA{sup IV} in its intact form, and then produces methylselenol, suggesting that MeSeCys is the best methylselenol source in most organs/tissues.
- OSTI ID:
- 21077923
- Journal Information:
- Toxicology and Applied Pharmacology, Vol. 227, Issue 1; Other Information: DOI: 10.1016/j.taap.2007.10.001; PII: S0041-008X(07)00447-4; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0041-008X
- Country of Publication:
- United States
- Language:
- English
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