Determination of nitrotyrosine concentrations in plasma samples of diabetes mellitus patients by four different immunoassays leads to contradictive results and disqualifies the majority of the tests

Safinowski, Michael; Wilhelm, Beate; Reimer, Tanja; Weise, Alexander; Thomé, Nicole; Hänel, Heike; Forst, Thomas; Pfützner, Andreas

doi:10.1515/cclm.2009.095

Cited by 20 publications

(12 citation statements)

References 36 publications

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“…It is well-documented that it accumulates with aging and in several OxS-related diseaes [35,49]. They are measured frequently in plasma or serum, where they are present in detectable amounts also in healthy individuals, while the tyrosine derivative 3-nitrotyrosine (formed by reaction with peroxynitrite or NO) which would be more specific for physiopathological assessment, is difficult to measure in blood or urine because of its high instability in these fluids [50][51][52].…”

Section: Protein Oxidationmentioning

confidence: 99%

Oxidative damage and the pathogenesis of menopause related disturbances and diseases

Cervellati

Bergamini

2016

Clinical Chemistry and Laboratory Medicine (CCLM)

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Abstract:The postmenopausal phase of life is frequently associated in women with subjective symptoms (e.g. vasomotor) and real diseases (atherosclerosis with coronary ischemia, osteoporosis, Alzheimer-type neurodegeneration, urogenital dystrophy), which together determine the post-menopausal syndrome. Observations that oxidative damage by reactive oxygen/nitrogen species in experimental models can contribute to the pathogenesis of these disturbances stimulated research on the relationships between menopause, its endocrine deficiency, oxidative balance and the "wellness" in postmenopausal life. The connection among these events is probably due to the loss of protective actions exerted by estrogens during the fertile life. Most recent studies have revealed that estrogens exert an antioxidant action not by direct chemical neutralization of reactants as it was expected until recently but by modulating the expression of antioxidant enzymes that control levels of biological reducing agents. Also nutritional antioxidants apparently act by a similar mechanism. From this perspective it is conceivable that a cumulative control of body oxidant challenges and biological defenses could help in monitoring between "normal" and "pathological" menopause. However, as clinical studies failed to confirm this scenario in vivo, we have decided to review the existing literature to understand the causes of this discrepancy and whether this was due to methodologic reasons or to real failure of the basic hypothesis.

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Section: Protein Oxidationmentioning

confidence: 99%

Oxidative damage and the pathogenesis of menopause related disturbances and diseases

Cervellati

Bergamini

2016

Clinical Chemistry and Laboratory Medicine (CCLM)

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“…Moreover, only a tiny percentage of the peroxynitrite molecules actually nitrate other compounds or macromolecules [11]. Finally, many laboratories (including our own) have experienced problems measuring nitrotyrosine, and the validity of HPLC [19] and immunologically based methods (which have been used in most published studies) has been challenged [11,30]. Convincing evidence of increased nitrotyrosine in clinical diabetes has been provided by only one laboratory, which used liquid chromatography and electrospray ionization tandem mass spectrometry [33].…”

Section: Nitrosative Stress In Diabetesmentioning

confidence: 99%

Oxidative stress and autonomic nerve function in early type 1 diabetes

2010

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“…Nitration of tyrosine residues results in loss of protein function or cell death and can contribute to disease pathogenesis [47, 48]. Unfortunately, the use of nitrotyrosine as a marker of nitrative stress is limited mainly due to analytical challenges associated with immunological assays, the most convenient and cost-effective method of measuring nitrotyrosine [49, 50]. More rigorous MS-based assays have circumvented these limitations, but artifactual formation of nitrotyrosine occurs during sample preparation if precautions are not taken [51, 52].…”

Section: Discussionmentioning

confidence: 99%

α-Tocopherol supplementation reduces 5-nitro-γ-tocopherol accumulation by decreasing γ-tocopherol in young adult smokers

Pei

Mah

Leonard

et al. 2015

Free Radical Research

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γ-Tocopherol (γ-T) scavenges reactive nitrogen species (RNS) to form 5-NO2-γ-tocopherol (NGT). However, α-T supplementation decreases circulating γ-T, which could limit its RNS scavenging activities. We hypothesized that α-T supplementation would mitigate NGT accumulation by impairing γ-T status. Healthy smokers (21±1 y, n=11) and non-smokers (21±2 y, n=10) ingested 75 mg/d each of RRR- and all rac-α-tocopheryl acetate for 6 d. Plasma α-T, γ-T, γ-carboxyethyl-hydroxychromanol (CEHC), NGT, and nitrate/nitrite were measured prior to supplementation (Pre), the morning after 6 consecutive evenings of supplementation (Post 1), and on the mornings of d 6 (Post 6) and d 14 (Post 14) during the post-supplementation period. α-T supplementation increased plasma α-T, and decreased γ-T, in both groups and these returned to Pre concentrations on Post 6 regardless of smoking status. Plasma γ-CEHC increased after the first dose of supplementation in both groups, suggesting that α-T supplementation decreased plasma γ-T in part by increasing its metabolism. Plasma NGT and nitrate/nitrite at Pre were greater in smokers, indicating greater nitrative stress due to cigarette smoking. Plasma NGT was lowered only in smokers on Post 1 and Post 6 and was restored to Pre levels on Post 14. Plasma nitrate/nitrite tended (P=0.07) to increase post-supplementation only in smokers, supporting decreases in RNS scavenging by γ-T. Plasma NGT was more strongly correlated (P<0.05) with γ-T in smokers (R=0.83) compared to non-smokers (R=0.50), supporting that α-T-mediated decreases in γ-T reduces NGT formation. These data indicate that α-T supplementation limits γ-T scavenging of RNS in smokers by decreasing γ-T availability.

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Determination of nitrotyrosine concentrations in plasma samples of diabetes mellitus patients by four different immunoassays leads to contradictive results and disqualifies the majority of the tests

Cited by 20 publications

References 36 publications

Oxidative damage and the pathogenesis of menopause related disturbances and diseases

Oxidative damage and the pathogenesis of menopause related disturbances and diseases

Oxidative stress and autonomic nerve function in early type 1 diabetes

α-Tocopherol supplementation reduces 5-nitro-γ-tocopherol accumulation by decreasing γ-tocopherol in young adult smokers

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