Pilot Study On The Role Of Nitric Oxide In Alpha 1-Adrenergic Vasoreactivity
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 22
- 试验地点
- 1
- 主要终点
- Determine whether alpha 1-adrenoceptor vasoreactivity is reproducible
研究概览
简要总结
This is a research project to test two study techniques among healthy adults. The procedures look at how blood flow is controlled by substances in blood vessels.
详细描述
Most patients with chronic kidney disease (CKD) have high blood pressure and are at high risk for cardiovascular disease. High blood pressure can be partly caused by narrowing of blood vessels from high activity of the alpha1-adrenoceptor system in blood vessels. On the other hand, nitric oxide (NO), produced by the body, opposes the alpha 1-adrenoceptor system. NO widens blood vessels and prevents high blood pressure. We hypothesize that low availability of NO may be responsible for high activity of alpha 1-adrenoceptor system in patients with CKD. This protocol is a pilot study in healthy subjects to guide us in performing future studies in patients with CKD.
The specific aims of the pilot study, in healthy people, are to 1) determine whether alpha 1-adrenoceptor vasoreactivity is reproducible and 2) determine alpha 1-adrenoceptor vasoreactivity with the NO clamp technique. To carry out these specific aims, we will consent and enroll healthy people with normal blood pressure. After a screening visit to confirm eligibility, subjects will be admitted to the General Clinical Research Center overnight for a study the following day.
We will constrict the forearm blood vessels by giving different amounts of phenylephrine into the artery through a catheter. We will measure the subjects blood flow with venus plethysmography ( a measuring tool like a blood pressure cuff) while giving the phenylephrine. We will repeat the tests to see if we get the same results.
Then, a research medication, L-NMMA, which blocks NO in the blood vessel, will be dripped into the same artery followed by another medication nitroprusside, which gives back NO, to restore normal forearm blood flow. This procedure is called the NO clamp technique and is used to measure the effects of NO. The phenylephrine concentrations and plethysmography will be repeated again to compare vessel narrowing before and during the NO clamp. This research will teach us how to perform future studies on the relationship between NO and the alpha 1-adrenoceptor system in patients with kidney disease.
研究设计
- 研究类型
- Interventional
- 分配方式
- Non Randomized
- 干预模型
- Single Group
- 主要目的
- Other
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 55 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Healthy men and women:
- •Age 18 to 55 years
- •Who have Blood Pressure less than or equal to 120/80.
排除标准
- •Individuals with:
- •Diabetes, lung disease
- •Stomach disease, liver disease
- •Blood vessel disease
- •Kidney disease
- •High blood pressure
- •Heart disease
- •Hereditary blood disorders
- •Hematocrit (amount of red blood cells) less than 30%,
- •Who smoke
- •Women who are pregnant or lactating
研究组 & 干预措施
phenylephrine infusion with and without nitric oxide clamp
Participants received phenylephrine infusion with saline followed by phenylephrine infusion with nitric oxide clamp
干预措施: Regional phenylephrine arterial infusion, Nitric Oxide Clamp (Drug)
结局指标
主要结局
Determine whether alpha 1-adrenoceptor vasoreactivity is reproducible
Determine alpha 1-adrenoceptor vasoreactivity with the NO clamp technique
次要结局
未报告次要终点
研究者
Crystal A. Gadegbeku
Assistant Professor of Medicine
University of Michigan