Low-density lipoprotein cholesterol determines oxidative stress and endothelial dysfunction in saphenous veins from patients with coronary artery disease.
OBJECTIVE
There is evidence for a relationship between endothelial dysfunction and cardiovascular disease, but a causative role for oxidative stress remains to be determined.


RESULTS
We studied 188 patients with severe coronary artery disease (CAD), of whom 51 were age and sex matched with 51 healthy controls undergoing varicose vein surgery. Relaxation of saphenous vein to calcium ionophore, apocynin, and allopurinol was studied together with the markers of oxidative stress, total antioxidant capacity and reduced/oxidized glutathione ratio. Vascular superoxide levels were measured using lucigenin chemiluminescence and hydroethidine. Relaxation to calcium ionophore was decreased in CAD compared with control patients (maximum relaxation 26+/-2% versus 60+/-1%; P<0.001). Total superoxide production was increased (0.89+/-0.09 versus 0.56+/-0.06 nmol/mg per min; P=0.008), whereas superoxide inhibition with apocynin or allopurinol had a greater effect on vasorelaxation in CAD patients. Low-density lipoprotein (LDL) cholesterol predicted relaxation to calcium ionophore (P<0.001) and oxidative stress markers (P<0.001) in CAD patients.


CONCLUSIONS
Endothelial dysfunction is associated with raised levels of superoxide and biomarkers of oxidative stress in saphenous veins from CAD patients. LDL cholesterol is a major determinant of endothelial dysfunction and oxidative stress in these patients. These results support intensive LDL cholesterol-lowering therapy as suggested by recent clinical trials.
Al-Benna
Sammy
S
BHF Glasgow Cardiovascular Research Centre, Division of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom.
Hamilton
Carlene A
CA
McClure
John D
JD
Rogers
Paul N
PN
Berg
Geoffrey A
GA
Ford
Ian
I
Delles
Christian
C
Dominiczak
Anna F
AF
D000098:Acetophenones / Q000494:pharmacology; D000328:Adult; D000368:Aged; D000493:Allopurinol / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology; D015415:Biomarkers; D008078:Cholesterol, LDL / Q000378:metabolism*; D003324:Coronary Artery Disease / Q000453:epidemiology / Q000378:metabolism* / Q000503:physiopathology*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology*; D005260:Female; D016166:Free Radical Scavengers / Q000494:pharmacology; D006801:Humans; D007476:Ionophores / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D009599:Nitroprusside / Q000494:pharmacology; D018384:Oxidative Stress / Q000502:physiology*; D010656:Phenylephrine / Q000494:pharmacology; D012307:Risk Factors; D012501:Saphenous Vein / Q000378:metabolism / Q000503:physiopathology; D013481:Superoxides / Q000378:metabolism; D014648:Varicose Veins / Q000378:metabolism / Q000503:physiopathology; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
D000098:Acetophenones; D000975:Antioxidants; D015415:Biomarkers; D008078:Cholesterol, LDL; D016166:Free Radical Scavengers; D007476:Ionophores; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D013481:Superoxides; D009599:Nitroprusside; D010656:Phenylephrine; D000493:Allopurinol; C056165:acetovanillone