Plasma F2 isoprostanes: direct evidence of increased free radical damage during acute hyperglycemia in type 2 diabetes.
OBJECTIVE
Acute hyperglycemia in type 2 diabetes increases the generation of plasma 8-epi-prostaglandin F2 (8-epi-PGF2alpha) isoprostane, a sensitive direct marker of in vivo free radical oxidative damage to membrane phospholipids.


METHODS
A total of 21 patients with type 2 diabetes underwent an oral 75-g glucose tolerance test. Plasma 8-epi-PGF2alpha isoprostane concentrations (by gas chromatography [GC]/mass spectrometry [MS]), intralymphocyte reduced-to-oxidized glutathione ratios, and plasma total antioxidant capacity were measured at baseline and 90 min after glucose loading.


RESULTS
Plasma 8-epi-PGF2alpha isoprostane concentrations rose significantly (P=0. 010) from 0.241 +/- 0.1 to 0.326 +/- 0.17 ng/l after 90 min. Intracellular oxidative balance and plasma antioxidant capacity did not change in either group.


CONCLUSIONS
Plasma concentrations of 8-epi-PGF2alpha isoprostane increase during acute hyperglycemia in type 2 diabetes, providing direct evidence of free radical-mediated oxidative damage and demonstrating a pathway for an association between acute rather than fasting hyperglycemia and macrovascular risk in type 2 diabetes.
Sampson
Michael J
MJ
Bertram Diabetes Research Unit, Norfolk and Norwich University Hospital National Health Service Trust, Norwich, UK. mike.sampson@norfolk-norwich.thenh.com
Gopaul
Nitin
N
Davies
Isabel R
IR
Hughes
David A
DA
Carrier
Martin J
MJ
D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000378:metabolism; D001786:Blood Glucose / Q000378:metabolism*; D002784:Cholesterol / Q000097:blood*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D015237:Dinoprost / Q000031:analogs & derivatives*; D028441:F2-Isoprostanes / Q000097:blood*; D005260:Female; D005609:Free Radicals / Q000097:blood; D008401:Gas Chromatography-Mass Spectrometry; D005951:Glucose Tolerance Test; D005978:Glutathione / Q000097:blood; D019803:Glutathione Disulfide / Q000097:blood; D006801:Humans; D006943:Hyperglycemia / Q000097:blood*; D008214:Lymphocytes / Q000378:metabolism; D008297:Male; D008875:Middle Aged
D000975:Antioxidants; D001786:Blood Glucose; D028441:F2-Isoprostanes; D005609:Free Radicals; C075750:8-epi-prostaglandin F2alpha; D002784:Cholesterol; D015237:Dinoprost; D005978:Glutathione; D019803:Glutathione Disulfide