Electrochemical detector for high-performance liquid chromatography. II. Determination of tocopherols, ubiquinones and phylloquinone in blood.

Ikenoya, Satoru; Abe, Koichi; Tsuda, Toshiro; Yamano, Y.; Hiroshima, Osamu; Ohmae, Masahiko; Kawabe, Kiyoshi

doi:10.1248/cpb.27.1237

Cited by 50 publications

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“…The effect of oxidation of aT on the Raman spectrum was studied by exposing aT supplemented A549 cells to H 2 O 2 . Briefly, cells were grown on glass coverslips and supplemented with zero or 50 M aT for 3 d. Cells were washed with prewarmed PBS and then exposed to 200 M H 2 O 2 in serum-free medium for 2 h. In parallel, lipids were extracted from cell homogenates as described before and the concentrations of aTQ were determined by HPLC, with electrochemical detection (23).…”

Section: Oxidative Stress Studiesmentioning

confidence: 99%

“…aT and other tocopherols are most commonly analyzed using HPLC with fluorescence, UV, or electrochemical detection (22,23). The concentrations of metabolites, nitration, or oxidation products, together with aT may, add valuable information about the redox balance in biological samples, but their determination mostly requires separate analyses (24,25).…”

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confidence: 99%

“…Generally, identification of aT in biological samples involves the extraction of lipid-soluble compounds with organic solvents (20,21) and the addition of antioxidants (e.g., butylated hydroxytoluene or ascorbic acid) may prevent oxidation during processing. aT and other tocopherols are most commonly analyzed using HPLC with fluorescence, UV, or electrochemical detection (22,23). The concentrations of metabolites, nitration, or oxidation products, together with aT may, add valuable information about the redox balance in biological samples, but their determination mostly re-quires separate analyses (24,25).…”

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confidence: 99%

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The use of Raman microscopy to determine and localize vitamin E in biological samples

et al. 2007

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Alpha-tocopherol (aT), the predominant form of vitamin E in mammals, is thought to prevent oxidation of polyunsaturated fatty acids. In the lung, aT is perceived to be accumulated in alveolar type II cells and secreted together with surfactant into the epithelial lining fluid. Conventionally, determination of aT and related compounds requires extraction with organic solvents. This study describes a new method to determine and image the distribution of aT and related compounds within cells and tissue sections using the light-scattering technique of Raman microscopy to enable high spatial as well as spectral resolution. This study compared the nondestructive analysis by Raman microscopy of vitamin E, in particular aT, in biological samples with data obtained using conventional HPLC analysis. Raman spectra were acquired at spatial resolutions of 2-0.8 microm. Multivariate analysis techniques were used for analyses and construction of corresponding maps showing the distribution of aT, alpha-tocopherol quinone (aTQ), and other constituents (hemes, proteins, DNA, and surfactant lipids). A combination of images enabled identification of colocalized constituents (heme/aTQ and aT/surfactant lipids). Our data demonstrate the ability of Raman microscopy to discriminate between different tocopherols and oxidation products in biological specimens without sample destruction. By enabling the visualization of lipid-protein interactions, Raman microscopy offers a novel method of investigating biological characterization of lipid-soluble compounds, including those that may be embedded in biological membranes such as aT.

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Section: Oxidative Stress Studiesmentioning

confidence: 99%

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The use of Raman microscopy to determine and localize vitamin E in biological samples

et al. 2007

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“…␣-Tocopherol was measured after extraction from the sample (33) by HPLC with electrochemical detection according to the method described by Ikenova et al (34). Samples were reconstituted in ethanol in a volume 1/10th of the volume initially used to give a 10 times concentration.…”

Section: Subjectsmentioning

confidence: 99%

Antioxidants and Protein Carbonyls in Bronchoalveolar Lavage Fluid of Children: Normal Data

et al. 2001

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Antioxidant-oxidant imbalances in bronchoalveolar lavage fluid (BAL) are thought to contribute to oxidative stress in respiratory disease. However, normal reference ranges for BAL antioxidants and oxidized proteins in children are not available. In this study, we recruited 124 children attending for elective surgery for a noninflammatory condition; 83 were nonasthmatic, nonatopic (N) and 41 were nonasthmatic, atopic (NA). A nonbronchoscopic lavage was performed and ascorbate, uric acid, ␣-tocopherol, and protein carbonyl (as a measure of oxidative damage) concentrations were determined in BAL fluid. The 95% reference range was 0.112-1.897 mol/L for ascorbate, 0.149 -2.163 mol/L for urate, 0.0029 -0.066 mol/L for ␣-tocopherol, and 0.280 -4.529 nmol/mg for protein carbonyls in BAL fluid. Age, gender, and exposure to environmental tobacco smoke did not affect the concentration of ascorbate, urate, ␣-tocopherol, or protein carbonyls. However, in multiple linear regression analyses, the type of home heating (glass-fronted fires or oil-fired central heating) was found to influence ascorbate and urate concentrations in the BAL fluid (␤-coefficient for ascorbate: 0.445, p ϭ 0.031; for urate: 0.114, p ϭ 0.001). There was no significant difference between the N and NA group in BAL fluid concentrations of ascorbate, urate, or protein carbonyls. The ␣-tocopherol concentration was significantly increased in the NA group (p ϭ 0.037). Uric acid and ␣-tocopherol concentrations in BAL fluid and serum were not correlated. Intriguingly, serum and BAL ascorbate concentrations were significantly correlated (r ϭ 0.297, p ϭ 0.018, n ϭ 63), which may offer an explanation for why supplementing the diet with vitamin C can improve asthma symptoms. Further studies will investigate the role of BAL antioxidant concentrations in children with inflammatory respiratory diseases. The epithelial lining fluid of the lungs contains relatively high concentrations of low molecular weight antioxidants such as ascorbic acid, uric acid, reduced glutathione (GSH), and ␣-tocopherol. They provide a first defense against inhaled exogenous oxidants such as SO 2 , NO 2 , CO, and O 3 and against endogenously produced oxidants (1-3). The increasing incidence of asthma, seen especially in children over the last two decades (4), has been linked to a reduced intake of antioxidant vitamins such as ascorbate, carotenoids, and ␣-tocopherol (5). Recently, Kelly et al. have found reduced ascorbate and ␣-tocopherol concentrations in the respiratory lining fluid of adults with mild asthma when compared with normal controls (6). An imbalance between antioxidants and oxidants in the epithelial lining fluid of the lung is thought to contribute to oxidative stress in respiratory disease (6).To determine the effect of respiratory diseases on the oxidant/antioxidant balance, it is important to know the concen-

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“…In the reduction (DME, 205 ' 411 Hg pool, 412 ' 413 amalgamated gold electrode 19 ) the detection limits are not as low as in the oxidation due to the reduction of O2, H + , and trace metals. 19 The following drugs have been determined in pharmaceutical preparations, body fluids, or tissues: acetaminophen, 119 ' 231 ' 415 ' 416 0-cetoterine, 125 8-hydroxycarteolol, 378 perphenazine and fluphenazine (coulometrically), 225 theophilline, 417 ' 418 tocopherols, 419 morphine, 454 apomorphine, 420 phenolic sympathomimetic stimulants," 8 ' 259 tricyclic antidepressants and their 2-hydroxy metabolites, 421 phenothiazine compounds, 422 benzodiazepines, 19 ' 89 chlorodiazepoxide and its metabolite, 411 trazepam, 205 …”

Section: G Drugs and Their Metabolitesmentioning

confidence: 99%

Electrochemical Detection in Hight-Performance Liquid Chromatography

Štulı́k¹,

Pacáková²,

Fleet³

1984

C R C Critical Reviews in Analytical Chemistry

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Electrochemical detector for high-performance liquid chromatography. II. Determination of tocopherols, ubiquinones and phylloquinone in blood.

Cited by 50 publications

References 0 publications

The use of Raman microscopy to determine and localize vitamin E in biological samples

The use of Raman microscopy to determine and localize vitamin E in biological samples

Antioxidants and Protein Carbonyls in Bronchoalveolar Lavage Fluid of Children: Normal Data

Electrochemical Detection in Hight-Performance Liquid Chromatography

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