At high cardiac output, diesel exhaust exposure increases pulmonary vascular resistance and decreases distensibility of pulmonary resistive vessels

Am J Physiol Heart Circ Physiol. 2015 Dec 15;309(12):H2137-44. doi: 10.1152/ajpheart.00149.2015. Epub 2015 Oct 23.


Air pollution has recently been associated with the development of acute decompensated heart failure, but the underlying biological mechanisms remain unclear. A pulmonary vasoconstrictor effect of air pollution, combined with its systemic effects, may precipitate decompensated heart failure. The aim of the present study was to investigate the effects of acute exposure to diesel exhaust (DE) on pulmonary vascular resistance (PVR) under resting and stress conditions but also to determine whether air pollution may potentiate acquired pulmonary hypertension. Eighteen healthy male volunteers were exposed to ambient air (AA) or dilute DE with a particulate matter of <2.5 μm concentration of 300 μg/m(3) for 2 h in a randomized, crossover study design. The effects of DE on PVR, on the coefficient of distensibilty of pulmonary vessels (α), and on right and left ventricular function were evaluated at rest (n = 18), during dobutamine stress echocardiography (n = 10), and during exercise stress echocardiography performed in hypoxia (n = 8). Serum endothelin-1 and fractional exhaled nitric oxide were also measured. At rest, exposure to DE did not affect PVR. During dobutamine stress, the slope of the mean pulmonary artery pressure-cardiac output relationship increased from 2.8 ± 0.5 mmHg · min · l (-1) in AA to 3.9 ± 0.5 mmHg · min · l (-1) in DE (P < 0.05) and the α coefficient decreased from 0.96 ± 0.15 to 0.64 ± 0.12%/mmHg (P < 0.01). DE did not further enhance the hypoxia-related upper shift of the mean pulmonary artery pressure-cardiac output relationship. Exposure to DE did not affect serum endothelin-1 concentration or fractional exhaled nitric oxide. In conclusion, acute exposure to DE increased pulmonary vasomotor tone by decreasing the distensibility of pulmonary resistive vessels at high cardiac output.

Keywords: air pollution; diesel exhaust; hypoxic pulmonary vasoconstriction; pulmonary hemodynamics; pulmonary vascular resistance.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Air Pollutants / toxicity*
  • Cardiac Output, High / physiopathology*
  • Cross-Over Studies
  • Echocardiography, Stress
  • Endothelin-1 / blood
  • Humans
  • Hypoxia / physiopathology
  • Male
  • Muscle, Smooth, Vascular / drug effects
  • Nitric Oxide / metabolism
  • Particulate Matter / adverse effects
  • Particulate Matter / analysis
  • Pulmonary Circulation / drug effects*
  • Rest
  • Vascular Resistance / drug effects*
  • Vasoconstriction / drug effects
  • Vehicle Emissions / toxicity*
  • Ventricular Function, Left / drug effects
  • Young Adult


  • Air Pollutants
  • Endothelin-1
  • Particulate Matter
  • Vehicle Emissions
  • Nitric Oxide