Dynamics of glutathione and ophthalmate traced with²H-enriched body water in rats and humans

Abstract

of glutathione and ophthalmate traced with 2 H-enriched body water in rats and humans.

Ophthalmate detection in human plasma with LC–MS–MS

“…An increasing number of studies have suggested that OPH could be a marker of hepatic GSH depletion [4][5][6][9][10][11]. However, most of these data are derived from animal experiments and human OPH data are scarce.…”

“…However, most of these data are derived from animal experiments and human OPH data are scarce. Kombu et al [6] investigated the GSH-OPH system by labelling free GSH, bound glutathione (GSSG) and OPH following intravenous infusion of 2 H-enriched water and subsequently used an LC-MS-MS assay to determine enrichments. This method provided the opportunity to measure the synthesis of these components in rat plasma, erythrocytes and liver.…”

“…1), an endogenous tripeptide analogue of GSH, has been suggested as a potential biomarker for GSH homeostasis as its production was found to be reciprocally promoted when GSH becomes depleted [4][5][6]. Kombu et al [5] suggested that when the hepatic availability of the amino acid cysteine, providing the reducing moiety of GSH, becomes limiting, the amino acid 2-aminobutyrate is incorporated instead, resulting in the formation of OPH [5].…”

Proteome Kinetics: Coupling the Administration of Stable Isotopes with Mass Spectrometry-Based Analyses

“…13 C-lysine) is that numerous protein-bound nitrogens will be labeled, therein increasing the window when measuring shifts in the isotope distribution of a proteolytic-peptide. A final approach to label the precursor pool centers on the administration of labeled water, either 2 H 2 O or H 2 18 O ( Figure 4C) (Cabral et al 2008;De Riva et al 2010;Kombu et al 2009;Rachdaoui et al 2009;Xiao et al 2008). The rationale is that cells will generate labeled amino acids in the presence of labeled water, e.g.…”

“…Despite the fact that studies based on the use of labeled water revolutionized our understanding of metabolic biochemistry nearly 80 years ago there appears to have been a dramatic shift away from the use of labeled water in the field of protein dynamics for reasons that remain unclear (Borek, Ponticorvo, and Rittenberg 1958;Schoenheimer and Rittenberg 1938;Ussing 1938;Ussing 1941;Ussing 1980). We, and others, have recently revisited the use of 2 H 2 O in studies of protein synthesis (Busch et al 2006;Cabral et al 2008;De Riva et al 2010;Kombu et al 2009;Previs et al 2004;Rachdaoui et al 2009;Xiao et al 2008), we also recognized the potential advantage(s) of using H 2 18 O (Bernlohr 1972;Bernlohr and Webster 1958;Borek, Ponticorvo, and Rittenberg 1958;Rachdaoui et al 2009;Rittenberg, Ponticorvo, and Borek 1961). Our use of H 2 18 O was based on a classical study in which Rittenberg and colleagues demonstrated that H 2 18 O could be used to study protein synthesis (the outstanding contributions of Bernlohr and others further tested the approach and more clearly outlined the logic) (Bernlohr 1972;Bernlohr and Webster 1958;Borek, Ponticorvo, and Rittenberg 1958;Rittenberg, Ponticorvo, and Borek 1961).…”