Simultaneous determination of retinol and alpha-tocopherol in serum or plasma by liquid chromatography.

Catignani, George L.; Bieri, John G.

doi:10.1093/clinchem/29.4.708

Cited by 532 publications

(133 citation statements)

References 5 publications

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“…Ascorbic acid was subsequently assayed by fluorimetry based on the condensation of dehydroascorbic acid with 1,2-phenylenediamine (Vuilleumier & Keck, 1993). Concentrations of α/γ-tocopherol, α/β-carotene, retinol, lycopene, zexanthin, β-cryptoxanthin and lutein were determined using an HPLC method (Catignani & Bieri, 1983;Thurnham et al 1988). The intra and interassay coefficients of variation were both <5%.…”

Section: Antioxidantsmentioning

confidence: 99%

Exercise-induced oxidative-nitrosative stress is associated with impaired dynamic cerebral autoregulation and blood-brain barrier leakage

Bailey

Evans

McEneny

et al. 2011

Experimental Physiology

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The present study examined whether dynamic cerebral autoregulation and blood-brain barrier function would become compromised as a result of exercise-induced oxidative-nitrosative stress. Eight healthy men were examined at rest and after an incremental bout of semi-recumbent cycling exercise to exhaustion. Changes in a dynamic cerebral autoregulation index were determined during recovery from continuous recordings of blood flow velocity in the middle cerebral artery (MCAv) and mean arterial pressure during transiently induced hypotension. Electron paramagnetic resonance spectroscopy and ozone-based chemiluminescence were employed for direct detection of spin-trapped free radicals and nitric oxide metabolites in venous blood. Neuron-specific enolase, S100β and 3-nitrotyrosine were determined by ELISA. While exercise did not alter MCAv, it caused a mild reduction in the autoregulation index (from 6.9 ± 0.6 to 5.5 ± 0.9 a.u., P < 0.05) that correlated directly against the exercise-induced increase in the ascorbate radical, 5-(diethoxyphosphoryl)-5-methyl-1-pyrroline N -oxide and N -tert-butyl-α-phenylnitrone adducts, 3-nitrotyrosine and S100β (r = -0.66 to -0.76, P < 0.05). In contrast, no changes in neuron-specific enolase were observed. In conclusion, our findings suggest that intense exercise has the potential to increase blood-brain barrier permeability without causing structural brain damage subsequent to a free radical-mediated impairment in dynamic cerebral autoregulation.

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Section: Antioxidantsmentioning

confidence: 99%

Exercise-induced oxidative-nitrosative stress is associated with impaired dynamic cerebral autoregulation and blood-brain barrier leakage

Bailey

Evans

McEneny

et al. 2011

Experimental Physiology

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show abstract

“…Thiobarbituric acid reactive substances (TBARS) were measured in blood and seminal plasma fluorometrically (Yagi, 1976). Oxidized glutathione (GSSG) was determined by HPLC (Asensi et al, 1994) while reduced glutathione (GSH) was measured following the glutathione-S-transferase assay (Brigelius et al, 1983), a-tocopherol (Buttriss & Diplock, 1984) and retinol (Catigiani & Bieri, 1983) content were determined by HPLC. The following antioxidant enzymes were also determined: catalase (Aebi, 1984), superoxide dismutase (SOD) (Flohé & Ö tting, 1984), gutathione peroxidase (GSH-Px) (Wheeler et al, 2001), glutathione transferase (GSH-Tr) (Habib et al, 1984) and glutathione reductase (GSH-Rd) (Callberg & Mannervick, 1985).…”

Section: Biochemical Assaysmentioning

confidence: 99%

Oxidative stress biomarkers and hormonal profile in human patients undergoing varicocelectomy

et al. 2007

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The aetiology of varicocele is multifactorial although hormonal imbalance and oxidative stress play a key role in the progression of illness. No conclusive evidence has been presented previously, describing the changes in these two factors and the evolution of patients after varicocelectomy. Semen characteristics and hormonal profile were analysed in 36 infertile men with unilateral left varicocele and 33 age-paired controls (proved to be fertile men), after careful inclusion/exclusion selection criteria. Liposoluble and hydrosoluble antioxidants, oligoelements and enzyme activities of the antioxidant defence system were also determined in plasma and erythrocyte from antecubital and spermatic veins, and in spermatozoa. Data were compared between groups at different times before and after varicocelectomy. Decreased levels of liposoluble and hydrosoluble antioxidants and increased activities of the antioxidant defence system enzymes were observed in patients compared with controls. Varicocelectomy normalized this condition at different post-surgical times. Levels of Zn and Se in seminal plasma, protein carbonyls and fragmented DNA remained elevated up to 1 month after surgery. Luteinizing and follicle stimulating hormone concentrations exhibited a biphasic behaviour while testosterone was diminished in patients but normalized soon after varicocelectomy. The results clearly demonstrate the link between the antioxidant defence system, hormonal status and semen characteristics along the post-varicocelectomy period. We suggest that oxidative biomarkers may be appropriate in controlling the evolution of post-varicocelectomy patients, and antioxidant supplementation may improve the clinical condition of infertile men with varicocele.

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“…HPLC with an electrochemical detector according to the method of Frei et al [14]. Alpha-tocopherol was determined by the modified HPLC method [15]. The protein SH-groups were determined according to Ellman [16].…”

Section: The Plasma Samplementioning

confidence: 99%

Is there an unidentified defence mechanism against infection in human plasma?

et al. 1996

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The total peroxyl radical scavenging capacity (TRAP) of human plasma was measured from pneumonia patients and controls. TRAP and its main components, ascorbic acid, alpha-tocopherol, uric acid or protein thiol groups, were unaltered, but the concentration of unidentified antioxidants in pneumonia patients was significantly reduced. Our results indicate that human plasma may contain so far unidentified antioxidants depleted in infection.

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Simultaneous determination of retinol and alpha-tocopherol in serum or plasma by liquid chromatography.

Cited by 532 publications

References 5 publications

Exercise-induced oxidative-nitrosative stress is associated with impaired dynamic cerebral autoregulation and blood-brain barrier leakage

Exercise-induced oxidative-nitrosative stress is associated with impaired dynamic cerebral autoregulation and blood-brain barrier leakage

Oxidative stress biomarkers and hormonal profile in human patients undergoing varicocelectomy

Is there an unidentified defence mechanism against infection in human plasma?

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