Effect of Oral L-Citrulline on the Peripheral and Central Endothelial Function in Young and Older Adults
试验速览
- 阶段
- 1 期
- 状态
- 已完成
- 入组人数
- 20
- 试验地点
- 1
- 主要终点
- Change in neurovascular coupling using the dynamic retinal vessel analysis
研究概览
简要总结
The effect of L-Citrulline is well studied in relation to muscle strength, exhaustion, exercise performance, and endothelial function in health and disease. This study will extend current body of knowledge and will investigate the effect of L-Citrulline on brain vascular function.
详细描述
Endothelial function is associated with nitric oxide (NO) availability for vasodilation, blood pressure and blood flow regulation, and vascular health. A large body of evidence demonstrates that aging is associated with a decrease in bioavailability of NO, with more pronounced decrease in sedentary individuals. NO can be produced via the NO synthase (NOS) enzymes, which catalyze the conversion of L-Arginine - a semi-essential amino acid found in fish, nuts and legumes amongst others - to L-Citrulline and produce NO as an endproduct. While the effect of L-Citrulline is extensively studied in relation to muscle strength, exhaustion, exercise performance, as well as on endothelial function in healthy and diseased individuals (including obese and those with heart failure), the effect of L-Citrulline on brain vascular function is not well studied.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Basic Science
- 盲法
- None
盲法说明
Open label
入排标准
- 年龄范围
- 18 Years 至 90 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Age 21-45 and ≥55-90 years of age
- •Adequate hearing and visual acuity to participate in the examinations
- •Ability to read and write in English
- •Competence to provide informed consent
排除标准
- •Active CNS disease including multiple sclerosis, uncontrolled seizures, active brain cancer
- •Cerebrovascular accident other than TIA within 60 days prior to Visit 0
- •Major psychiatric disease, including major depression not currently controlled on medications, alcohol or drug abuse
- •Treatment with other Citrulline enhancers (L-Arginine, L-Citrulline Malate) within 4 weeks prior to Visit 0
- •Any other medical condition which, in the opinion of investigator, would render the patient inappropriate or too unstable to complete the study protocol
研究组 & 干预措施
L-Citrulline
L-Citrulline 50 g/day per os for 1 week
干预措施: L-Citrulline, capsule (Drug)
结局指标
主要结局
Change in neurovascular coupling using the dynamic retinal vessel analysis
时间窗: 1 week
Flicker light-induced dilation of the retinal vessels (percentage increase over baseline diameter) will be measured in the right or left eye of each study participant using the Dynamic Vessel Analyzer (DVA, IMEDOS Systems, Jena, Germany). Units of measure mm, reported as a %change from baseline, before and after treatment.
Change in neuronal activity
时间窗: 1 week
EEG signal will be collected to generate spectral data. These data will be used for comparison of EEG activity between before and after treatment. Units of measure - power spectral density. Reported as a %change from baseline, before and after treatment.
Change in neurovascular coupling using functional near infrared spectroscopy (fNIRS)
时间窗: 1 week
Functional near infrared spectroscopy (fNIRS) will be performed during the cognitive n-back task. fNIRS approach generates data that represent a relative change in oxygenated and deoxygenated hemoglobin measured over the cortical brain tissues. Neurovascular coupling will be evaluated as a change in oxy- and deoxy-hemoglobin between before and after treatment. Units of measure - beta. Reported as a %change from baseline, before and after treatment.
次要结局
- Change in Processing Speed(1 week)
- Change in Glycocalyx - perfused boundary region(1 week)
- Change in grip strength(1 week)
- Change in macrovascular endothelial function(1 week)
- Change in Attention(1 week)
- Blood collection(1 week)
- Change in microvascular endothelial function(1 week)
- Change in red blood cell velocity(1 week)
- Change in Executive Function(1 week)
- Change in capillary density(1 week)
- Change in Working Memory(1 week)