The place of electron spin resonance methods in the detection of oxidative stress in type 2 diabetes with poor glycemic control.
OBJECTIVE
Chronic production of reactive oxygen species (ROS) and/or deficiency in the antioxidant defense system are observed in non-insulin-dependent diabetes mellitus (NIDDM) patients. As an adjunct to the usual indirect parameters for evaluating oxidative stress, we assessed the feasibility of oxyradicals detection in venous blood by electron spin resonance spectroscopy (ESR). Detection of the ascorbate pool was also performed using the validated ESR analysis of the ascorbyl free radial (AFR)-dimethyl sulfoxide (DMSO) complex.


RESULTS
Plasma lipoperoxidation was characterized by higher levels of total MDA (1.50 +/- 0.08 nmol/L), lower levels of GSH (0.54 +/- 0.02 mmol/L) and of vitamin A (2.13 +/- 0.52 mumol/L) in the NIDDM group than in the controls (0.75 +/- 0.05 nmol/L, 0.90 +/- 0.05 mmol/L, 3.52 +/- 1.04 mumol/L, respectively). Improvement of the ESR measurement of oxyradical adducts has been previously obtained by addition of a new sensitive nitrone (DEPMPO), which acts as a spin-trap. However, in our experiment the ESR signal-to-noise ratio was too low to detect significative oxyradicals adducts in total venous blood of NIDDM patients having a weak production of ROS. A significant difference (p < 0.002) was observed in DMSO/AFR index between controls (24.00 +/- 4.10 nmol/L) and NIDDM patients (7.28 +/- 2.36 nmol/L) suggesting ascorbate depletion related to the free radical production.


CONCLUSIONS
The DMSO/AFR index could be an interesting additional marker of oxidative stress during a chronic production of ROS.
Delmas-Beauvieux
M C
MC
RMSB UMR 5536, CNRS-Université Victor Segalen, Bordeaux, France. cath@rmsb.u-bordeaux2.fr
Peuchant
E
E
Thomas
M J
MJ
Dubourg
L
L
Pinto
A P
AP
Clerc
M
M
Gin
H
H
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000975:Antioxidants / Q000378:metabolism; D001205:Ascorbic Acid / Q000032:analysis; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000201:enzymology / Q000378:metabolism*; D004121:Dimethyl Sulfoxide / Q000032:analysis; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D005260:Female; D005609:Free Radicals / Q000097:blood; D005978:Glutathione / Q000097:blood; D006801:Humans; D006943:Hyperglycemia / Q000097:blood / Q000201:enzymology / Q000378:metabolism*; D015227:Lipid Peroxidation; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D008875:Middle Aged; D018384:Oxidative Stress; D019097:Spin Trapping; D014815:Vitamins / Q000097:blood
D000975:Antioxidants; D005609:Free Radicals; D014815:Vitamins; D008315:Malondialdehyde; D005978:Glutathione; D001205:Ascorbic Acid; D004121:Dimethyl Sulfoxide