View clinical trials related to Vasodilation.
Filter by:Endothelin-1 (ET-1) has been linked to a number of conditions including pulmonary arterial hypertension (PAH). ET-1 acts via 2 receptors, ETA and ETB. The ET-1 receptor blockers bosentan and sitaxsentan have been shown to be beneficial in patients with PAH. Bosentan blocks both ETA and ETB receptors. Sitaxsentan selectively blocks ETA receptors. Theoretically, selective ETA blockade may be associated with greater vasodilation and clearance of ET-1 by leaving the ETB receptor unblocked. This has not been directly studied in humans. We aim to investigate the endothelial ETB-mediated vascular responses between bosentan and sitaxsentan by using a ETB selective agonist (ET-3). We hypothesise that at clinically relevant doses: - Bosentan will show evidence of ETB receptor blockade compared to sitaxsentan and placebo. - These effects will be confirmed by 2 functional markers of ETB receptor antagonism: plasma ET-1 (a very sensitive, but not necessarily clinically relevant marker), and the forearm vasodilator response to ET-3.
The apelin-APJ system is a relatively new discovery. It has generated interest in part due to it's apparent ability to counteract the renin-angiotensin system, which is frequently overactive in many cardiovascular disease. Angiotensin has a powerful ability to cause blood vessels constrict and reduces their diameter. One of the actions of apelin is to cause blood vessels to relax and the investigators specifically wish test the hypothesis that apelin will cause blood vessels constricted by angiotensin II to relax.
The apelin-APJ system is a relatively new discovery. It has generated interest in part due to it's apparent ability to counteract the renin-angiotensin system, which is frequently overactive in many cardiovascular disease. Apelin has the ability to cause blood vessels to relax, increasing their diameter and hence blood flow down the blood vessel. The researchers wish to investigate the hypothesis that an infusion of apelin will reduce the effects of angiotensin II, which is know to reduce the diameter of blood vessels.
The purpose of this study is to compare changes of minimally invasive arterial pulse contour cardiac output with changes of intermittent and continuous thermodilution cardiac output by pulmonary artery catheter in hemodynamic unstable patients with rapid changing vascular tone (changing dosage of vasoactive drugs or inotropics, or volume challenge). Simultaneously, global parameters of oxygen delivery and consumption will be compared with regional flow parameters and tissue oxymetry (near infrared spectrometry and laser-Doppler). While continuous thermodilution cardiac output is used for patient management, pulse contour cardiac output, intermittent thermodilution cardiac output and tissue oxymetry is only used for monitoring.
Diet has long been used as a way to provide enough nutrients to an individual in order to meet metabolic requirements. However, recent scientific advancements have suggested that beyond meeting nutrition needs, diet may also be health promoting through the modulation of various body functions. In a way, the role of nutrition has evolved from hunger satisfaction and maintenance of body integrity to the promotion of a state of well-being and prevention of important chronic diseases such as cancer, diabetes and cardiovascular disease (CVD). In recent years, n-3 polyunsaturated fatty acids (PUFA) have attracted much attention as consumption of a n-3 PUFA rich diet has been reported to reduce CVD risk. However, n-3 PUFA are also highly susceptible to free radical damage and therefore could be unable to fully exert their health benefits under an oxidative stress condition. The general objective of the present application is to investigate the mechanisms by which n-3 PUFA improve cardiovascular health in abdominal obesity and explore the potential of dietary antioxidants to modulate these effects in individuals at high risk of oxidative stress. For that purpose, we plan to study the changes in fasting and postprandial plasma lipoprotein-lipid levels, markers of lipid and lipoprotein oxidation, inflammation and endothelial dysfunction following 12 weeks of n-3 PUFA supplementation with or without low-calorie cranberry juice cocktail (as a source of antioxidants) in a group of 160 men. We feel that the present study will broaden our understanding of the physiological mechanisms underlying the beneficial effects of consuming unsaturated fatty acids and give further insights on the role of antioxidants in preserving and potentiating these cardiovascular health benefits.
In this study we aim to determine whether methotrexate influences the metabolism and vascular effects of adenosine in humans in vivo. Adenosine is an endogenous purine-nucleoside with potent anti-inflammatory effects. Also, adenosine receptor stimulation induces vasodilation, ischaemic preconditioning and many other cardiovacular effects. Previous animal studies have provided limited evidence that the anti-inflammatory effects of methotrexate are mediated by adenosine receptor stimulation. In this study, we aim to determine whether also in humans in vivo, methotretate influences endogenous adenosine. Therefore, 10 patients with inflammatory arthritis are treated with methotretxae (15 mg/week orally) for 12 weeks. Before and after treatment, vasodilation to the infusion of adenosine and dipyridamole into the brachial artery is assessed as biomarker for the endogenous adenosine concentration. Also, blood is drawn for the determination of CRP, ESR, Adenosine deaminase activity adn homocysteine.