Persistent Endothelial Dysfunction in Humans after Diesel Exhaust Inhalation

Rationale: Exposure to combustion-derived air pollution is associated with an early (1–2 h) and sustained (24 h) rise in cardiovascular morbidity and mortality. We have previously demonstrated that inhalation of diesel exhaust causes an immediate (within 2 h) impairment of vascular and endothelial function in humans.Objectives: To investigate the vascular and systemic effects of diesel exhaust in humans 24 hours after inhalation.Methods: Fifteen healthy men were exposed to diesel exhaust (particulate concentration, 300 μg/m3) or filtered air for 1 hour in a double-blind, randomized, crossover study. Twenty-four hours after exposure, bilateral forearm blood flow, and inflammatory and fibrinolytic markers were measured before and during unilateral intrabrachial bradykinin (100–1,000 pmol/min), acetylcholine (5–20 μg/min), sodium nitroprusside (2–8 μg/min), and verapamil (10–100 μg/min) infusions.Measurements and Main Results: Resting forearm blood flow, blood pressure, and basal fibrinolytic markers were si...