Evaluation of endothelial free radical release by vascular tension responses in insulin-resistant rat aorta.
Mechanical responses to superoxide anion scavengers and nitric oxide (NO) synthase inhibitors in aortic endothelial cells were compared in normal chow-fed rats and those made insulin-resistant by feeding of fructose. Cu(2+), Zn(2+)-superoxide dismutase-induced vascular relaxation and superoxide production, measured by the lucigenin-enhanced chemiluminescence method, were greater in aortas from fructose-fed rats than in those from normal chow-fed rats. N(G)-nitro-L-arginine-induced contractions due to suppression of NO synthase activity were smaller in aortas from fructose-fed rats. Vascular mechanical responses may reflect the generation of superoxide and NO by the endothelium. Thus, isometric tension studies may be a useful tool for evaluating the production of these radicals in blood vessels.
Shinozaki
K
K
Third Department of Medicine, Shiga University of Medical Science, Seta, Otsu, Japan.
Okamura
T
T
Nishio
Y
Y
Kashiwagi
A
A
Kikkawa
R
R
Toda
N
N
D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects / Q000378:metabolism*; D001794:Blood Pressure / Q000187:drug effects; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005609:Free Radicals / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000494:pharmacology; D066298:In Vitro Techniques; D007328:Insulin / Q000494:pharmacology; D007333:Insulin Resistance / Q000502:physiology*; D007537:Isometric Contraction; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism; D019335:Nitroarginine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013482:Superoxide Dismutase / Q000494:pharmacology; D013481:Superoxides / Q000378:metabolism
D004791:Enzyme Inhibitors; D005609:Free Radicals; D007004:Hypoglycemic Agents; D007328:Insulin; D013481:Superoxides; D019335:Nitroarginine; D009569:Nitric Oxide; D013482:Superoxide Dismutase