Determination of 2-mercaptopropionylglycine and its metabolite, 2-mercaptopropionic acid, in plasma by ion-pair reversed-phase high-performance liquid chromatography with post-column derivatization

Leroy, Pierre; Nicolas, Alain; Gavriloff, C.; Matt, Muriel; Netter, Patrick; Bannwarth, B; Hercelin, B; Mazza, M. Adam

doi:10.1016/0378-4347(91)80088-t

Cited by 26 publications

(10 citation statements)

References 15 publications

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“…Elimination of intracellular ROS was achieved using the ROS scavenger N ‐(2‐mercaptopropionyl) glycine (MPG; 0.5 m m ) (Leroy et al . ). Elimination of mitochondrial O 2 •− was achieved using the mitochondrial O 2 •− scavenger MitoTEMPO (20 μ m ).…”

Section: Methodsmentioning

confidence: 97%

Decreases in mitochondrial reactive oxygen species initiate GABA_A receptor‐mediated electrical suppression in anoxia‐tolerant turtle neurons

Hogg

Pamenter

Dukoff

et al. 2015

The Journal of Physiology

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Key pointsr Anoxia induces hyper-excitability and cell death in mammalian brain but in the western painted turtle (Chrysemys picta bellii) enhanced GABA transmission prevents injury.r The mechanism responsible for increased GABA transmission is unknown; however, reactive oxygen species (ROS) generated by mitochondria may play a role because this is an oxygen-sensitive process.r In this study, we show that inhibition of mitochondrial ROS production is sufficient to initiate a redox-sensitive GABA signalling cascade that suppresses pyramidal neuron action potential frequency.r These results further our understanding of the turtle's unique strategy for reducing ATP consumption during anoxia and highlights a natural mechanism in which to explore therapies to protect mammalian brain from low-oxygen insults (e.g. cerebral stroke).Abstract Anoxia induces hyper-excitability and cell death in mammalian brain but in the anoxia-tolerant western painted turtle (Chrysemys picta bellii) neuronal electrical activity is suppressed (i.e. spike arrest), adenosine triphosphate (ATP) consumption is reduced, and cell death does not occur. Electrical suppression is primarily the result of enhanced γ-aminobutyric acid (GABA) transmission; however, the underlying mechanism responsible for initiating oxygen-sensitive GABAergic spike arrest is unknown. In turtle cortical pyramidal neurons there are three types of GABA A receptor-mediated currents: spontaneous inhibitory postsynaptic currents (IPSCs), giant IPSCs and tonic currents. The aim of this study was to assess the effects of reactive oxygen species (ROS) scavenging on these three currents since ROS levels naturally decrease with anoxia and may serve as a redox signal to initiate spike arrest. We found that anoxia, pharmacological ROS scavenging, or inhibition of mitochondrial ROS generation enhanced all three types of GABA currents, with tonic currents comprising ß50% of the total current. Application of hydrogen peroxide inhibited all three GABA currents, demonstrating a reversible redox-sensitive signalling mechanism. We conclude that anoxia-mediated decreases in mitochondrial ROS production are sufficient to initiate a redox-sensitive inhibitory GABA signalling cascade that suppresses electrical activity when oxygen is limited. This unique strategy for reducing neuronal ATP consumption during anoxia represents a natural mechanism in which to explore therapies to protect mammalian brain from low-oxygen insults.

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Section: Methodsmentioning

confidence: 97%

Decreases in mitochondrial reactive oxygen species initiate GABA_A receptor‐mediated electrical suppression in anoxia‐tolerant turtle neurons

Hogg

Pamenter

Dukoff

et al. 2015

The Journal of Physiology

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“…MPG becomes oxidized to disulfide dimers and forms conjugates with other endogenous thiols [11]. Previous methods used for determining the quantitation of MPG include an electrochemical detection system [12], gas chromatography-mass spectrometry [13], and the HPLC method [14].…”

Section: Introductionmentioning

confidence: 99%

Liquid chromatography analysis of N-(2-mercaptopropionyl)-glycine in biological samples by ThioGlo™ 3 derivatization

Penugonda

Mare

et al. 2004

Journal of Chromatography B

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N-(2-Mercaptopropionyl)-glycine (MPG) is a synthetic aminothiol antioxidant that is used in the treatment of cystinuria, rheumatoid arthritis, liver and skin disorders. Recent studies have shown that MPG can function as a chelating, cardioprotecting and a radioprotecting agent. Several other studies have shown that it may also act as a free radical scavenger because of its thiol group. Thiol-containing compounds have been detected in biological samples by various analytical methods such as spectrophotometric and colorimetric methods. However, these methods require several milliliters of a sample, time-consuming procedures and complicated derivatization steps, as well as having high detection limits. The present study describes a rapid, sensitive and relatively simple method for detecting MPG in biological tissues by using reverse-phase HPLC. With ThioGlo 3 [3H-Naphto[2,1-b] pyran, 9-acetoxy-2-(4-(2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl) phenyl-3-oxo-)] as the reagent, highly fluorescent derivatives of thiols can be obtained that are suitable for HPLC. MPG is derivatized with ThioGlo 3 and is then detected flourimetrically by reverse phase HPLC using a C18 column as the stationary phase. Acetonitrile: Water (75:25) with acetic acid and phosphoric acid (1 mL/L) is used as the mobile phase (excitation wavelength, 365 nm; emission wavelength, 445 nm). The calibration curve for MPG is linear over a range of 10-2500 nM (r=0.999) and the coefficients of the variation of within-run and between-run precision were found to be 0.3 and 2.1%, respectively. The detection limit was 5.07 nM per 20 microL injection volume. Quantitative relative recovery of MPG in the biological samples (plasma, lung, liver, kidney and brain) ranged from 90+/-5.3 to 106.7+/-9.3 %. Based on these results, we have concluded that this method is suitable for determining MPG in biological samples.

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“…As indicated earlier, the thiol compound was unstable in plasma sample due to their tendency for oxidation to disulfides. 10 Although many reducing agents have been applied for thiol stability during sample collection, the use of reducer can increase the complexity of a sample processing and possess its own distinctive challenges to the method development process, especially for MS analysis. According to the report of Lai et al, 11 HCl is useful to stabilize tiopronin in rat plasma.…”

Section: Methods Validationmentioning

confidence: 99%

Stereoselective analysis of tiopronin enantiomers in rat plasma using high‐performance liquid chromatography‐electrospray ionization mass spectrometry after chiral derivatization

Wang

Zhou

et al. 2008

Chirality

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A specific and relatively sensitive high-performance liquid chromatography-electrospray ionization mass spectrometry (HPLC-ESI-MS) was developed for the quantitative analysis of tiopronin enantiomers in rat plasma. The method is based on the derivatization of (+)-tiopronin and (-)-tiopronin with 2,3,4,6-tetra-O-acetyl-beta-glucopyranosyl isothiocyanate (GITC) in acetonitrile. The separation of resulting diastereomic derivatives was performed on C18 column (150 mm x 2.0 mm ID, packed with 5.0 mum C(18) silica RP particle), using a mobile phase of methanol/water (containing 5.3 mM formic acid) with gradient elution. LC-MS was performed in the selected ion monitoring and positive ion mode using target ions at m/z: 575 for the diastereomic derivatives of tiopronin and m/z: 603 for the derivative of N-isobutyryl-D-cysteine (internal standard). The method was validated in terms of specificity, linearity, sensitivity, precision, accuracy, matrix effect, and stability. The calibration curves were linear over the concentration range of 0.025-5 microg/ml for both enantiomers of tiopronin. For both enantiomers of tiopronin, the interbatch and intrabatch variability values were less than 15%, and the accuracy was within +/-17% in terms of relative error. The method was successfully applied to a pharmacokinetic study of rac-tiopronin in rat.

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Determination of 2-mercaptopropionylglycine and its metabolite, 2-mercaptopropionic acid, in plasma by ion-pair reversed-phase high-performance liquid chromatography with post-column derivatization

Cited by 26 publications

References 15 publications

Decreases in mitochondrial reactive oxygen species initiate GABA_A receptor‐mediated electrical suppression in anoxia‐tolerant turtle neurons

Decreases in mitochondrial reactive oxygen species initiate GABA_A receptor‐mediated electrical suppression in anoxia‐tolerant turtle neurons

Liquid chromatography analysis of N-(2-mercaptopropionyl)-glycine in biological samples by ThioGlo™ 3 derivatization

Stereoselective analysis of tiopronin enantiomers in rat plasma using high‐performance liquid chromatography‐electrospray ionization mass spectrometry after chiral derivatization

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Determination of 2-mercaptopropionylglycine and its metabolite, 2-mercaptopropionic acid, in plasma by ion-pair reversed-phase high-performance liquid chromatography with post-column derivatization

Cited by 26 publications

References 15 publications

Decreases in mitochondrial reactive oxygen species initiate GABAA receptor‐mediated electrical suppression in anoxia‐tolerant turtle neurons

Decreases in mitochondrial reactive oxygen species initiate GABAA receptor‐mediated electrical suppression in anoxia‐tolerant turtle neurons

Liquid chromatography analysis of N-(2-mercaptopropionyl)-glycine in biological samples by ThioGlo™ 3 derivatization

Stereoselective analysis of tiopronin enantiomers in rat plasma using high‐performance liquid chromatography‐electrospray ionization mass spectrometry after chiral derivatization

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Product

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Decreases in mitochondrial reactive oxygen species initiate GABA_A receptor‐mediated electrical suppression in anoxia‐tolerant turtle neurons

Decreases in mitochondrial reactive oxygen species initiate GABA_A receptor‐mediated electrical suppression in anoxia‐tolerant turtle neurons