Enhanced, unaltered and impaired nitric oxide-mediated endothelium-dependent relaxation in experimental diabetes mellitus: importance of disease duration.

摘要: Long-term diabetes mellitus is characterized by impaired endothelium-dependent relaxation. In contrast, there limited information on endothelial function in the early stages of disease. this study, we evaluated ex vivo at early, intermediate and later streptozotocin (STZ)-induced mellitus. We also contribution various endothelium-derived vasoactive factors these aortic rings contracted with norepinephrine, relaxation to acetycholine was increased 24 h following injection compared controls, normal after 1 2 weeks disease or 8 Endothelium-independent nitroglycerin unaltered all stages. The enhanced mimicked from alloxan-induced diabetic rats. Acute exposure vitro caused no perturbation acetylcholine-stimulated Enhanced persisted presence either indomethacin tetraethylammonium. Acetylcholine-induced blocked both control using l-nitroarginine but not aminoguanidine. This suggests that response mediated constitutive nitric oxide (NO). These studies show a triphasic increased, within same model dependent duration could reconcile previous conflicting data literature account for observations increases tissue blood flow seen experimental human [Diabetologia (1999) 42: 204–213]