Variability in Adrenergic Response
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 106
- 试验地点
- 1
- 主要终点
- ED50 After Phenylephrine
研究概览
简要总结
The goal of this project is to determine the genetic factors contributing to interindividual differences in response to physiological and pharmacological vasoconstrictors and vasodilators.
详细描述
The dorsal hand vein model is a relatively non-invasive and robust experimental model to examine the local in vivo effect of vasoactive drugs without elucidating systemic counterregulatory reflexes. Infusion of incremental low doses of phenylephrine into a dorsal hand vein results in increasing local venoconstriction, without systemic effects. Similarly, infusion of incremental low doses of nitroglycerin into a preconstricted dorsal hand vein results in increasing local venodilation, without systemic effects. Systemic vascular responses can be measured by the cold pressor test (CPT),that leads to increase in blood pressure and heart rate , or mental stress that is also known to stimulate cardiovascular responses. Individuals vary in their local and systemic vascular responses but the genetic determinants of these are not clear.
研究设计
- 研究类型
- Interventional
- 分配方式
- Non Randomized
- 干预模型
- Parallel
- 主要目的
- Other
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 40 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Age between 18 and 40 years, inclusive.
- •Subject must be willing to give written informed consent and be able to adhere to diet and study schedules.
- •Subjects must be free of any clinically significant disease that requires a physician's care and/or would interfere with the study evaluations.
- •Subjects must have a normal or clinically acceptable physical examination and ECG.
- •Clinical laboratory tests (CBC, blood chemistries, and urinalysis) must be within normal limits or clinically acceptable to the investigator.
排除标准
- •Any subject who has taken any prescription or over-the-counter drugs, other than oral contraception if female, within two weeks prior to study drug administration.
- •Subjects who are presently, or were formerly, narcotic addicts or alcoholics.
- •Subjects who have a clinically significant allergy/intolerance to phenylephrine.
- •Females with a positive serum/urine pregnancy test at screening.
- •Females who are nursing.
- •Subject using sildenafil or other phosphodiesterase inhibitors.
研究组 & 干预措施
African Americans
Subjects' hand veins will be measured for maximum constriction while being infused with phenylephrine, and then mental stress and cold pressor testing
干预措施: Phenylephrine (Drug)
Caucasians
Subjects' hand veins will be measured for maximum constriction while being infused with phenylephrine, and then mental stress and cold pressor testing
干预措施: Phenylephrine (Drug)
结局指标
主要结局
ED50 After Phenylephrine
时间窗: 70 minutes
ED50 is a measurement of vein constriction and indicates 50% of maximal constriction after being given medication phenylephrine, representing sensitivity to the drug. Phenylephrine was infused at increasing dose rates, ranging from 12-9600 ng/min. The infusion at each dose rate lasted 7 minutes, with the vein diameter measured during the last 2 minutes of the infusion. The number represents the ng/ml of phenylephrine needed to reach 50% of maximal vein constriction. ED50 values were not normally distributed and were log-transformed for analysis and expressed as geometric means.
次要结局
- Change in Blood Pressure(baseline to 2 minutes)
研究者
C. Michael Stein
Dan May Professor of Medicine, Professor of Pharmacology, Assistant Director of the Division of Clinical Pharmacology
Vanderbilt University