3-nitro-L-tyrosine - biomarker of nitrosative stress?
- 08.04.2002
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H. Schmandke, Bergholz-Rehbrücke
Endogenous nitric oxide is formed from arginine and molecular oxygen by NO synthase enzymes. NO· may react with other radicals and hence it has antioxidant properties. However, the excessive formation of NO· in combination with superoxide anions (O2· –) leads to lipid peroxidation (oxidative stress) and nitration of proteins (nitrosative stress).
Under hydrophobic conditions, nitration of tyrosine to 3-nitrotyrosine (NO2Tyr) is a predominant reaction. In humans, there are levels of free and of protein-bound NO2Tyr. The metabolic pathways of free NO2Tyr are unknown. Antioxidants inhibit the production of protein NO2Tyr. Dietary nitrate and nitrite do obviously not elevate the levels of blood plasma protein-bound NO2Tyr.
In case of arteriosclerosis, smokers and lung cancer the protein-bound NO2Tyr values are increased in blood plasma. NO2Tyr therefore is a potential indicator of nitrosative stress. EU04/02
Keywords: 3-nitro-L-tyrosine / nitrosative stress / biomarker
Sie finden den Artikel in deutscher Sprache in Ernährungs-Umschau 04/02 ab Seite 133.
