Effects of diabetes on plasma nitrotyrosine levels.
BACKGROUND
Oxidative stress plays a major role in disease processes such as atherosclerosis and diabetes. Peroxynitrite is a reaction product of nitric oxide (NO) and superoxide and a potent oxidant. The peroxynitrite-mediated tyrosine nitration, which forms nitrotyrosine (NT), is associated with several pathological conditions.


METHODS
We measured plasma NT levels using the HPLC method in 40 Mexican Americans with diabetes, but not taking medications, and 40 age- and sex-matched euglycaemic controls.


RESULTS
Plasma-free NT levels were not different between subjects with diabetes (11.0 +/- 1.7 nmol/l, n = 40) and with non-diabetes (10.4 +/- 1.5 nmol/l, n = 40). There was also no association with levels of fasting glucose (r = -0.049, P = 0.663) or 2-h glucose (r = -0.099, P = 0.390). However, females had significantly lower free NT level (7.6 +/- 1.4 nmol/l, n = 40) than males (13.8 +/- 1.7 nmol/l, n = 40, P = 0.005), which were not affected by age, smoking status, BMI and glucose levels.


CONCLUSIONS
In contrast to some earlier reports, our study shows that diabetes has no effect on plasma NT levels in Mexican Americans. We have also demonstrated lower free NT levels in females than males, which may partly explain the lower risk profile to vascular disease in women.
Wang
X L
XL
Division of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas 77030, USA. xlwang@bcm.tmc.edu
Rainwater
D L
DL
Leone
A
A
Mahaney
M C
MC
D001786:Blood Glucose / Q000032:analysis; D003920:Diabetes Mellitus / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012737:Sex Factors; D012907:Smoking; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000097:blood*
D001786:Blood Glucose; C002744:3-nitrotyrosine; D014443:Tyrosine