A control systems approach to quantify wall shear stress normalization by flow-mediated dilation in the brachial artery.

Flow-mediated dilation is aimed at normalization of local wall shear stress under varying blood flow conditions. Blood flow velocity and vessel diameter are continuous and opposing influences that modulate wall shear stress. We derived an index FMDv to quantify wall shear stress normalization performance by flow-mediated dilation in the brachial artery.

Pressure-dependence of arterial stiffness: potential clinical implications.

Background: Arterial stiffness measures such as pulse wave velocity (PWV) have a known dependence on actual blood pressure, requiring consideration in cardiovascular risk assessment and management. Given the impact of ageing on arterial wall structure, the pressure-dependence of PWV may vary with age.

Methods: Using a noninvasive model-based approach, combining carotid artery echo-tracking and tonometry waveforms, we obtained pressure-area curves in 23 hypertensive patients at baseline and after 3 months of antihypertensive treatment.

Endothelial function in migraine: a cross-sectional study.

Background: Migraine has been associated with cardiovascular disorders. Endothelial dysfunction may be a mechanism underlying this association. The present study tested the hypothesis that endothelium-dependent vasodilation, basal endothelial nitric oxide release and endothelial fibrinolytic capacity are impaired in migraine patients.

Inhibition of capsaicin-induced increase in dermal blood flow by the oral CGRP receptor antagonist, telcagepant (MK-0974).

What Is Already Known About This Subject: * Calcitonin gene-related peptide (CGRP) was first described as a potent vasodilator. * CGRP is also increasingly recognized as a key player in the pathophysiology of migraine, and CGRP receptor antagonists potentially offer a new approach for treating migraine. * A novel pharmacodynamic assay to measure CGRP receptor antagonist activity non-invasively in humans has been developed, which involves measuring the increase in dermal blood flow induced by topical application of capsaicin on the forearm.

Altered arterial function in migraine of recent onset.

Objective: Migraine is associated with cardiovascular disorders but the underlying mechanisms are unknown. Arterial structure and function are important determinants of cardiovascular morbidity and mortality. The aim of the present study was to assess arterial properties in patients with migraine of recent onset.

Acute effects of sumatriptan on aortic blood pressure, stiffness, and pressure waveform.

Background And Objectives: Sumatriptan, a 5-hydroxytryptamine (HT)(1B/1D) receptor agonist, is an effective acute antimigraine drug. Because of its vasoconstrictor activity, it is contraindicated in patients at high risk for adverse cardiovascular events. Acute antimigraine drugs without vasoconstrictor effects are currently being developed, and sensitive, noninvasive techniques by which to detect drug-induced vascular effects would facilitate their clinical development.

Calcitonin gene-related peptide-induced vasodilation in the human forearm is antagonized by CGRP8-37: evaluation of a human in vivo pharmacodynamic model.

Objectives: The aims of this study were to assess the potential of CGRP8-37, the C-terminal fragment of calcitonin gene-related peptide (CGRP), to inhibit CGRP-induced vasodilation in the human forearm and to evaluate a pharmacodynamic model to aid the clinical development of novel CGRP-receptor antagonists.

Methods: Forearm blood flow (FBF) responses to intra-arterial CGRP infusions were measured via venous occlusion plethysmography in 21 healthy subjects. Dose response to CGRP was assessed during graded infusion of CGRP (1, 3, and 10 ng.

Reproducibility of forearm vasodilator response to intra-arterial infusion of calcitonin gene-related peptide assessed by venous occlusion plethysmography.

Aims: To assess the reproducibility of the forearm blood flow (FBF) response to intra-arterial infusion of calcitonin-gene related peptide (CGRP), measured by venous occlusion plethysmography. In addition, to compare different ways of expressing the FBF response and perform sample size calculations.

Methods: On two separate visits, CGRP (10 ng min(-1) dl(-1) forearm) was infused for 45 min into the brachial artery of six healthy subjects.