View clinical trials related to Cardiovascular System.
Filter by:Cardiovascular disease is the leading cause of mortality worldwide. Endothelial dysfunction (ED) is the main mechanism which leads to atherosclerosis, where the balance between pro and antioxidant factors results in a decreased nitric oxide (NO) bioavailability. Xanthine OxidoReductase (XOR) is one of the main generators of reactive oxygen species (ROS). Uric acid (UA), a major antioxidant in human plasma and end product of purine metabolism, is associated with cardiovascular diseases since many years; however the precise mechanisms which relate UA to ED are still not well understood. The purpose of this study is to unravel the XOR and UA pathways involved in ED. Three groups of participants (young (< 40 y) male healthy participants [1] ; male and female helthy participants (40 to 65 y) [2] and patients with primary hypertension [3]) will be exposed to febuxostat (a strong and selective XOR inhibitor), or recombinant uricase (which oxidizes UA into allantoin) to vary UA levels and concomitantly control for confounding changes in XOR activity. Oxidative stress will be estimated by several markers. Endothelial function will be assessed by a laser Doppler imager in the presence of hyperthermia and endothelium stimulators. This study is specifically designed to untie the respective effects of UA and XOR pathways on oxidative stress and endothelial function in humans. The investigators will test the following hypothesis: 1. An extremely low level of uric acid after uricase administration induces endothelial dysfunction and oxydative stress, 2. A specific XO inhibitor limits unfavourable effects of the serum UA reduction elicited by uricase administration, 3. Endothelial function and oxydative stress are further improved with febuxostat as compared to placebo, 4. All these observations are more marked in hypertensives then in older participants than in young healthy subjects.
This study is designed to investigate the cardiovascular response (blood pressure, heart rate, electrocardiographic response and blood vessel reactivity response) to taking Adderall in healthy adults.
This is a pilot study to investigate whether patients at advanced age are fluid responders via a reversible fluid challenge, the passive leg raise test. This will be measured with a non-invasive cardiac output monitor, the LiDCO (LiDCO Hemodynamic monitoring) .
This study is being done to look at the cardiovascular response, if any, to intake of commercially available energy drink. We hypothesize that energy drink consumption compared to a control drink in healthy adults alters the cardiovascular hemodynamic system.The focus of this study is to elucidate the physiological/cardiovascular response to an energy drink consumption as compared to a control drink both at rest and during stressful conditions in healthy adults.