Atherosclerosis impairs flow-mediated dilation of coronary arteries in humans.

Atherosclerosis impairs flow-mediated dilation of coronary arteries in humans.

Studies in animals have suggested that increases in blood flow result in dilation of large arteries by an endothelium-dependent mechanism. Atherosclerosis can impair endothelium-dependent vasodilation to vasoactive agents. The purpose of this study was to determine whether or not large coronary arteries in humans exhibit dilation with increases in blood flow and to test the hypothesis that this...

Assessment of Flow Mediated Dilation (fmd) in Humans:

Endothelium-mediated coronary blood flow modulation in humans. Effects of age, atherosclerosis, hypercholesterolemia, and hypertension.

The effects of age, atherosclerosis, hypertension, and hypercholesterolemia on vascular function of the coronary circulation were studied by subselective intracoronary infusions of acetylcholine, which releases endothelium-derived relaxing factor, and papaverine, which directly relaxes vascular smooth muscle, in normal patients (n = 18; no risk factors for coronary artery disease), in patients ...

Mitochondrial sources of H2O2 generation play a key role in flow-mediated dilation in human coronary resistance arteries.

We previously showed that hydrogen peroxide (H2O2) contributes to flow-induced dilation in human coronary resistance arteries (HCRAs); however, the source of this H2O2 is not known. We hypothesized that the H2O2 is derived from superoxide (O2*-) generated by mitochondrial respiration. HCRAs were dissected from right atrial appendages obtained from patients during cardiac surgery and cannulated ...

Role of caveolae in shear stress-mediated endothelium-dependent dilation in coronary arteries.

AIMS Caveolae are membrane microdomains where important signalling pathways are assembled and molecular effects transduced. In this study, we hypothesized that shear stress-mediated vasodilation (SSD) of mouse small coronary arteries (MCA) is caveolae-dependent. METHODS AND RESULTS MCA (80-150 μm) isolated from wild-type (WT) and caveolin-1 null (Cav-1(-/-)) mice were subjected to physiologic...