Journal Article

Diesel Exhaust Inhalation Elicits Acute Vasoconstriction in Vivo

Carlsten, Chris, Gill, Edward A., Peretz, Alon, Wilkinson, Charles W., Leotta, Daniel F., Sands, Fiona N., Allen, Jason, Kaufman, Joel D., Sullivan, Jeffrey H., Trenga, Carol A.

2008

Overview

Background: Traffic-related air pollution is consistently associated with cardiovascular morbidity and mortality. Recent human and animal studies suggest that exposure to air pollutants affects vascular function. Diesel exhaust (DE) is a major source of traffic-related air pollution. Objectives: Our goal was to study the effects of short-term exposure to DE on vascular reactivity and on mediators of vascular tone. Methods: In a double-blind, crossover, controlled exposure study, 27 adult volunteers (10 healthy and 17 with metabolic syndrome) were exposed in randomized order to filtered air (FA) and each of two levels of diluted DE (100 or 200$\\mu {\\rm g}/{\\rm m}^{3}$of fine particulate matter) in 2-hr sessions. Before and after each exposure, we assessed the brachial artery diameter (BAd) by B-mode ultrasound and collected blood samples for endothelin-1 (ET-1) and catecholamines. Postexposure we also assessed endothelium-dependent flow-mediated dilation (FMD). Results: Compared with FA, DE at$200\\ \\mu {\\rm g}/{\\rm m}^{3}$elicited a decrease in BAd (0.11 mm; 95% confidence interval, 0.02-0.18), and the effect appeared linearly dose related with a smaller effect at$100\\ \\mu {\\rm g}/{\\rm m}^{3}$. Plasma levels of ET-1 increased after$200\\ \\mu {\\rm g}/{\\rm m}^{3}$DE but not after FA (p = 0.01). There was no consistent impact of DE on plasma catecholamines or FMD. Conclusions: These results demonstrate that short-term exposure to DE is associated with acute endothelial response and vasoconstriction of a conductance artery. Elucidation of the signaling pathways controlling vascular tone that underlie this observation requires further study.

• Publisher: National Institute of Environmental Health Sciences
• Subject: Adult / Air pollutants / Air pollution / Blood plasma / Brachial artery / Brachial Artery - diagnostic imaging / Brachial Artery - drug effects / Brachial Artery - physiopathology / Catecholamines / Catecholamines - metabolism / Control / Cross-Over Studies / Diesel engines / Diesel exhaust / Diesel motor exhaust gas / Dose-Response Relationship, Drug / Double-Blind Method / Endothelin-1 - metabolism / Environmental aspects / Exposure / Female / Health aspects / Humans / Inhalation / Inhalation Exposure - adverse effects / Male / Metabolic disorders / Metabolic Syndrome - metabolism / Metabolic Syndrome - physiopathology / Metabolism / Middle Aged / Particulate matter / Particulate Matter - toxicity / Physiological aspects / Risk factors / Time Factors / Ultrasonography / Vasoconstriction / Vasoconstriction - drug effects / Vasodilation - drug effects / Vehicle Emissions - toxicity