OBJECTIVES We sought to determine whether the antioxidant vitamin C improves endothelium-dependent vasodilation of forearm resistance vessels in patients with insulin-dependent diabetes mellitus. BACKGROUND Endothelium-dependent vasodilation is impaired in patients with diabetes mellitus. Oxidatively mediated degradation of endothelium-derived nitric oxide contributes to abnormal endothelium-...

In 1980 Furchgott and Zawadzki discovered that acetylcholine-induced relaxation of rabbit aortic strips required an intact endothelium. They found that stimulation of muscarinic receptors on the endothelium led to the release of a non-prostanoid relaxing factor which they named endothelium-derived relaxing factor. Further studies have established the importance of endothelium-derived relaxing f...

Andresen, Jon, Nadeem I. Shafi, and Robert M. Bryan Jr. Endothelial influences on cerebrovascular tone. J Appl Physiol 100: 318–327, 2006; doi: 10.1152/japplphysiol.00937.2005.—The cerebrovascular endothelium exerts a profound influence on cerebral vessels and cerebral blood flow. This review summarizes current knowledge of various dilator and constrictor mechanisms intrinsic to the cerebrovasc...

The effect of hypoxia on endothelium-dependent and endothelium-independent vasodilation was studied in phenylephrine-precontracted, isolated rings of rabbit first-branch pulmonary artery. Concentration-dependent relaxation responses to the endothelium-dependent dilators methacholine, ATP, and the calcium ionophore (A23187) as well as to the endothelium-independent dilators sodium nitroprusside ...

The endothelium regulates vascular tone through the release of a number of soluble mediators, including NO, prostaglandin I2, and endothelium-derived hyperpolarizing factor. Epoxyeicosatrienoic acids are cytochrome P450 epoxygenase metabolites of arachidonic acid. They are synthesized by the vascular endothelium and open calcium-activated potassium channels, hyperpolarize the membrane, and rela...

The present study was designed to test the ability of regenerated endothelium to evoke endothelium-dependent hyperpolarizations. Hyperpolarizations induced by serotonin and bradykinin were compared in isolated porcine coronary arteries with native or regenerated endothelium, 4 weeks after balloon endothelial denudation. The experiments were performed in the presence of inhibitors of nitric oxid...

1. The present study examined effects of arginine (Arg) and various Arg analogues on the vascular tone of rabbit and rat aortic rings, the release of nitrite from cultured bovine aortic endothelial cells and the metabolism of L-Arg in bovine and porcine endothelial cell homogenates. The respective D-enantiomers or N-alpha-benzoyl-L-arginine ethyl ester did not substitute for L-Arg. 2. In bovine...