Diesel Exhaust Inhalation, Systemic Nitric Oxide Inhibition and Cardiac Output
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 14
- 试验地点
- 1
- 主要终点
- Blood pressure response to NO inhibition
研究概览
简要总结
Exposure to combustion-derived fine particulate air pollution is associated with cardiovascular mortality and morbidity. In previous studies, exposure to diesel exhaust (a major constituent of urban particulate air pollution) has been shown to impair two important functions of the vascular endothelium: vascular vasomotor function and endogenous fibrinolysis. Our subsequent studies suggest this impairment of vascular function is mediated by a reduction in nitric oxide bioavailability. In this study we aim to investigate the cardiovascular responses to systemic nitric oxide synthase inhibition following exposure to dilute diesel exhaust.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- Triple (Participant, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Healthy volunteers
- •Non smokers
- •No regular medication (except oral contraceptive)
- •No recent respiratory tract infection (within 6 weeks)
排除标准
- •History of asthma or respiratory disease
- •Smoking history
- •Pregnancy (positive urinary pregnancy test)
研究组 & 干预措施
Diesel exhaust exposure
1 hour exposure to dilute diesel exhaust ~ 300 mcg/m3 - during intermittent exercise
干预措施: Intravenous infusion of L-NMMA and Nor-epinephrine (Drug)
Air exposure
1 hour exposure to filtered air during intermittent exercise
干预措施: Intravenous infusion of L-NMMA and Nor-epinephrine (Drug)
结局指标
主要结局
Blood pressure response to NO inhibition
时间窗: Blood pressure will be measured continuously through the vascular study using intra-arterial monitoring
次要结局
- Heart rate response to systemic nitric oxide inhibition(Heart rate will be measured continuously throughout the study period using continous electrocardiography)
- Central arterial stiffness following NO inhibition(Measured at baseline, and every 5 minutes during the 2-hour vascular study)
- Cardiac output during NO inhibition(Measured at baseline, and every 5 minutes during the 2-hour vascular study)
- Plasma nitrite (NO) concentrations(Measured at baseline, and every 15 minutes during the 2-hour vascular study)
- Platelet activation and platelet-monocyte binding(Measured at baseline, and every 30 minutes during the 2-hour vascular study)
- Heart rate variability(Heart rate will be measured continuously throughout the study period using continous electrocardiography, and HRV subsequently determined for the whole study period and the 2-hour vascular study separately)