Journal
XENOBIOTICA
Volume 46, Issue 4, Pages 379-384Publisher
TAYLOR & FRANCIS LTD
DOI: 10.3109/00498254.2015.1075259
Keywords
Mouse PAH variants; pharmacokinetics; S-carboxymethyl-L-cysteine; S-carboxymethyl-L-cysteine (R/S) S-oxides; Sulfoxides
Categories
Ask authors/readers for more resources
The extent of sulfoxidation of the drug, S-carboxymethyl-L-cysteine, has been shown to vary between individuals, with this phenomenon being mooted as a biomarker for certain disease states and susceptibilities. Studies in vitro have indicated that the enzyme responsible for this reaction was phenylalanine monooxygenase but to date no in vivo evidence exists to support this assumption. Using the mouse models of mild hyperphenylalaninamia (enu1 PAH variant) and classical phenylketonuria (enu2 PAH variant), the sulfur oxygenation of S-carboxymethyl-L-cysteine has been investigated. Compared to the wild type (wt/wt) mice, both the heterozygous dominant (wt/enu1 and wt/enu2) mice and the homozygous recessive (enu1/enu1 and enu2/enu2) mice were shown to have significantly increased C-max, AUC((0-180 min)) and AUC((0-infinity min)) values (15 -to 20-fold higher). These results were primarily attributable to the significantly reduced clearance of S-carboxymethyl-L-cysteine (13 - to 22-fold lower). Only the wild type mice produced measurable quantities of the parent S-oxide metabolites. Those mice possessing one or more allelic variant showed no evidence of blood SCMC (R/S) S-oxides. These observations support the proposition that differences in phenylalanine hydroxylase activity underlie the variation in S-carboxymethyl-L-cysteine sulfoxidation and that no other enzyme is able to undertake this reaction.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available