The Role of Nitric Oxide Synthase Isoforms in the Cardiovascular Effects of Air Pollution

Not Applicable

Completed

• Conditions: Endothelial Dysfunction
• Interventions: Procedure: Forearm vascular study

• Registration Number: NCT00845169
• Lead Sponsor: University of Edinburgh

Brief Summary

Exposure to air pollution has been linked to increased cardiorespiratory morbidity and mortality. The exact component of air pollution that mediates this effect is unknown, but the link is strongest for fine combustion derived particulate matter derived from traffic sources. Recently, it has been demonstrated that inhalation of diesel exhaust impairs vascular vasomotor tone and endogenous fibrinolysis. The mechanism underlying these detrimental vascular is unclear, but is thought to be via oxidative stress and altered bioavailability of endogenous nitric oxide. In these studies we plan to elucidate the role of endogenous nitric oxide synthase isoforms (NO) in the adverse vascular responses observed following exposure to diesel exhaust.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2009-02-17
• Study First Submitted QC: 2009-02-17
• Study First Posted: 2009-02-18
• Study Start: 2012-04
• Primary Completion: 2013-06
• Study Completion: 2013-06
• Status Verified: 2014-12
• Last Update Submitted: 2014-12-01
• Last Update Posted: 2014-12-02

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 16

Inclusion Criteria

• Healthy volunteers

Exclusion Criteria

• Regular medication use (except oral contraceptive pill)
• Current smokers
• Significant occupational exposure to air pollution
• Intercurrent illness

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Diesel Exposure	Forearm vascular study	1 hour exposure to diesel exhaust at 300 µg/m3 during intermittent exercise
Air Exposure	Forearm vascular study	1 hour exposure to filtered air during intermittent exercise

Primary Outcome Measures

Name	Time	Method
Forearm blood flow measured by venous occlusion plethysmography during intraarterial infusion of nitric oxide synthase inhibitors L-NMMA, SMTC and 1400W and positive control norepinephrine.	2-4 hours after exposure

Secondary Outcome Measures

Name	Time	Method
Plasma nitrite concentration	During forearm study

Trial Locations

Locations (1)

Umeå University; 🇸🇪 Umeå, Sweden