Internal standard method for the measurement of choline and acetylcholine by capillary electrophoresis with electrochemical detection

Wise, Dana D.; Barkhimer, Tatyana V.; Brault, Pierre-Alexandre; Kirchhoff, Jon R.; Messer, William S.; Hudson, Richard

doi:10.1016/s1570-0232(02)00269-6

Cited by 33 publications

(42 citation statements)

References 36 publications

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“…H 2 O 2 released from the reactor can be detected with to a suitable detector placed in the downstream. Because the detection potentials for H 2 O 2 were usually high (+0.7 ~ +0.9 V vs. SCE) at a Pt electrode [16], many substances such as ascorbic acid or uric acid in biological fluids can interfere with the measurements without the separation procedures. In order to rejecting the electroactive interferences, an alternative approach was proposed by use of Pt electrode modified with the electrosynthesized polymeric membrane [15].…”

Section: Inductionmentioning

confidence: 99%

Enzymatic flow injection method for rapid determination of choline in urine with electrochemiluminescence detection

Jin

Muroga

Takahashi

et al. 2010

Bioelectrochemistry

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In order to determine trace choline in human urine, a flow injection analysis (FIA) system has been developed by coupling of an enzyme reactor with an electrochemiluminescence (ECL) detector. The enzyme reactor is prepared by covalently immobilizing of choline oxidase (ChOx) onto the aminopropyl-controlled pore glass beads, which are then carefully packed into a micro column. The enzyme reactor catalyzes the production of hydrogen peroxide that is in direct proportion to the concentration of choline. In this study, the enzymatically produced hydrogen peroxide was detected by an ECL detector positioned at the down stream of enzyme reactor based on the luminol/H 2 O 2 ECL system. Under the optimized condition, the enzymatic FIA/ECL provided high sensitivity for the determination of choline with the detection limit as low as 0.05 M (absolute detection limit was at sub pmol level). The method was successfully applied in the determination of choline in the samples of human urine, and the analytical results were in good agreement with those obtained by using the microbore HPLC with immobilized enzyme reactor-electrochemical detection system.

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Section: Inductionmentioning

confidence: 99%

Enzymatic flow injection method for rapid determination of choline in urine with electrochemiluminescence detection

Jin

Muroga

Takahashi

et al. 2010

Bioelectrochemistry

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“…Ch concentrations were analyzed using BuCh as an internal standard. 17,18 Evaluation of the inhibition properties of 6 and 7 utilized the Ch transport assay methods developed by Barkhimer et al 11,19 using mouse synaptosomes as the CHT model. Synaptosome suspensions were prepared from C57BL6 adult male mice (Harlan Sprague Dawley, Indianapolis, IN) following the general procedure of Gray and Whittaker, 23 as modified by Patel.…”

Section: Methodsmentioning

confidence: 99%

“…The preparation of the enzyme modified microelectrode was previously described in detail. 17 The enzyme microelectrode tip was carefully aligned with the capillary outlet by placing both the electrode and the capillary inside a custom made detection cell (Allied Plastics, Toledo, OH, USA). 22 Alignment in this manner optimized physical contact with the flowing liquid at the end of the capillary and minimized disruption of the enzyme layer.…”

Section: Instrumentationmentioning

confidence: 99%

Inhibition of choline transport by redox-active cholinomimetic bis-catechol reagents

Cai¹,

Mukherjee²,

Tillekeratne³

et al. 2007

Bioorganic & Medicinal Chemistry

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Both N,N′-(2,3-dihydroxybenzyl)-N,N,N′,N′-tetramethyl-1,6-hexanediamine dibromide (DTH,6) and N,N′-(2,3-dihydroxybenzyl)-N,N,N′,N′-tetramethyl-1,10-decanediamine dibromide (DTD, 7), which are symmetrical bis-catechol substituted hexamethonium and decamethonium analogues, respectively, were found to inhibit high affinity choline transport in mouse brain synaptosomes. Inhibitory properties were evaluated using an extraordinarily sensitive capillary electrophoresis method employing electrochemical detection at an enzyme-modified microelectrode. Dose-response curves were generated for each inhibitor and IC 50 values were determined to be 76 μM for 6 and 21 μM for 7. Lineweaver-Burk analysis revealed that both molecules inhibit high affinity choline uptake by a mixed inhibition mechanism. The K I values for 6 and 7 were determined to be 73 ± 1 and 31 ± 2 μM, respectively. The inhibition properties were further compared to a series of mono-catechol analogues, 3-[(trimethylammonio)methyl]catechol (1), N,N-dimethylepinephrine (4) and 6-hydroxy-N,N-dimethylepinephrine (5), as well as the well-characterized hemicholinium inhibitors, hemicholinium-15 (HC-15, 8) and hemicholinum-3 (HC-3, 9).

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“…Microchipintegrated CEECD has been developed and tested with biomedical samples, showing excellent analytical performance and good technological potential for microfabrication [335]. The effort to develop CEECD applications focuses on the analysis of neurochemically and metabolically important small biogenic and essential molecules, including amino acids [336][337][338][339][340][341][342], monoamines [343][344][345][346][347][348][349][350][351][352], excitatory and inhibitory neurotransmitters with low electrochemical activity [342,353], and some vitamins and cofactors such as ascorbic acid and glutathione [354][355][356][357][358][359][360][361][362][363][364].…”

Section: Electrochemical Detection (Ecd)-electrochemical Detection (Ementioning

confidence: 99%

Bioanalytical profile of the l-arginine/nitric oxide pathway and its evaluation by capillary electrophoresis

Boudko

2007

Journal of Chromatography B

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This review briefly summarizes recent progress in fundamental understanding and analytical profiling of the L-arginine/nitric oxide (NO) pathway. It focuses on key analytical references of NO actions and on the experimental acquisition of these references in vivo, with capillary electrophoresis (CE) and high-performance capillary electrophoresis (HPCE) comprising one of the most flexible and technologically promising analytical platform for comprehensive high-resolution profiling of NO-related metabolites. Second aim of this review is to express demands and bridge efforts of experimental biologists, medical professionals and chemical analysis-oriented scientists who strive to understand evolution and physiological roles of NO and to develop analytical methods for use in biology and medicine.

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Internal standard method for the measurement of choline and acetylcholine by capillary electrophoresis with electrochemical detection

Cited by 33 publications

References 36 publications

Enzymatic flow injection method for rapid determination of choline in urine with electrochemiluminescence detection

Enzymatic flow injection method for rapid determination of choline in urine with electrochemiluminescence detection

Inhibition of choline transport by redox-active cholinomimetic bis-catechol reagents

Bioanalytical profile of the l-arginine/nitric oxide pathway and its evaluation by capillary electrophoresis

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