CO may directly activate calcium-dependent potassium channels, thus mediating dilation of blood vessels [ 57].
We found no evidence that flow mediated dilation, an indirect measure of NO, is altered by multidose administration of hawthorn standardized extract.
We examined endothelial function (by flow mediated dilation, FMD, a measure of EDNO), intima-media thickness (IMT, a measure of subclinical atherosclerosis) and large artery stiffness by pulse wave velocity (PWV, a measure of arteriosclerosis).
While these two studies were performed using brachial artery flow mediated dilation, that is, analysis of a large conductance artery, we show that the NO-dependent second peak to local heating is impaired in RA, suggesting an abnormality of the microvascular endothelium.
This was accompanied by a decrease in brachial artery flow-mediated dilation consistent with an impact of raised FFA level, with or without inflammation, on endothelial function (10).
A sphygmomanometer blood pressure cuff was then secured on the left forearm just distal to the elbow for assessment of flow mediated dilation [ 26].
Further evidence comes from the notable improvements in endothelial function which lead to increased flow mediated dilation [4, 5] and increased flexibility of the vascular system, also known as augmentation [6, 7].
However, it has been questioned whether the EndoPAT measurements are directly comparable to other assessments of endothelial dysfunction, like flow mediated dilation, since hyperaemia is captured by finger probes as compared to vasodilation assessment of larger arteries [ 27].
Analysis revealed an increase in brachial artery diameters following the submaximal exercise bout, which may influence the degree of both FMD and NTG-mediated dilation.
In fact a recent dose response study using conventionally processed cocoa powder in ever increasing amounts has found that as little as 5 g is sufficient to elicit significant vasodilation of the brachial artery, as measured by Flow Mediated Dilation [27].
