Particulate Matter Exposure Impairs Systematic Microvascular Endothelium-Dependent Dilation

Details

• Personal Author:
  Barger M ; Boegehold MA ; Castranova, Vincent ; Nurkiewicz TR ; Porter DW
• Description:
  Acute exposure to airborne pollutants, such as solid particulate matter (PM), increases the risk of cardiovascular dysfunction, but the mechanisms by which PM evokes systemic effects remain to be identified. The purpose of this study was to determine if pulmonary exposure to a PM surrogate, such as residual oil fly ash (ROFA), affects endothelium-dependent dilation in the systemic microcirculation. Rats were intratracheally instilled with ROFA at 0.1, 0.25, 1 or 2 mg/rat 24 hr before experimental measurements. Rats intratracheally instilled with saline or titanium dioxide (0.25 mg/rat) served as vehicle or particle control groups, respectively. In vivo microscopy of the spinotrapezius muscle was used to study systemic arteriolar dilator responses to the Ca2+ ionophore A23187, administered by ejection via pressurized micropipette into the arteriolar lumen. We used analysis of bronchoalveolar lavage (BAL) samples to monitor identified pulmonary inflammation and damage. To determine if ROFA exposure affected arteriolar nitric oxide sensitivity, sodium nitroprusside was iontophoretically applied to arterioles of rats exposed to ROFA. In saline-treated rats, A23187 dilated arterioles up to 72 +/- 7% of maximum. In ROFA- and TiO2-exposed rats, A23187-induced dilation was significantly attenuated. BAL fluid analysis revealed measurable pulmonary inflammation and damage after exposure to 1 and 2 mg ROFA (but not TiO2 or < 1 mg ROFA), as evidenced by significantly higher polymorphonuclear leukocyte cell counts, enhanced BAL albumin levels, and increased lactate dehydrogenase activity in BAL fluid. The sensitivity of arteriolar smooth muscle to NO was similar in saline-treated and ROFA-exposed rats, suggesting that pulmonary exposure to ROFA affected endothelial rather than smooth muscle function. A significant increase in venular leukocyte adhesion and rolling was observed in ROFA-exposed rats, suggesting local inflammation at the systemic microvascular level. These results indicate that pulmonary PM exposure impairs systemic endothelium-dependent arteriolar dilation. Moreover, because rats exposed to < 1 mg ROFA or TiO2 did not exhibit BAL signs of pulmonary damage or inflammation, it appears that PM exposure can impair systemic microvascular function independently of detectable pulmonary inflammation. [Description provided by NIOSH]
• Subjects:
  Air Pollutants, Occupational Animals Cardiovascular Diseases Cardiovascular System Laboratories Lung Diseases Occupational Health Particulate Matter Respiratory Tract Diseases Risk Assessment Risk Factors Safety

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• Keywords:
  Airborne Particles Animal Studies Author Keywords: Arteriole Cardiovascular System Disorders Endothelium In Vivo Studies Laboratory Animals Nitric Oxide Particulate Matter Particulates Pollutants Pulmonary System Disorders Residual Oil Fly Ash Risk Factors ROFA Spinotrapezius Muscle Systemic Microcirculation Titanium Dioxide

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• ISSN:
  0091-6765
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  112
• Issue:
  13
• NIOSHTIC Number:
  nn:20025331
• Citation:
  Environ Health Perspect 2004 Sep; 112(13):1299-1306
• Contact Point Address:
  T.R. Nurkiewicz, Department of Physiology and Pharmacology, Box 9229, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26506-9229 USA
• Email:
  tnurkiewicz@hsc.wvu.edu
• CAS Registry Number:
  Nitric oxide (CAS RN 10102-43-9) ; Titania (CAS RN 13463-67-7)
• Federal Fiscal Year:
  2004
• Peer Reviewed:
  True
• Source Full Name:
  Environmental Health Perspectives
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:641c71b1f4d0fcab651a272e49a788943d5f23976499bca30c8923f9c15a089556dddaafb4ba293abb9375ea39d6d285ccd0b05deb54525a1024fb2674b897cb
• Download URL:
  https://stacks.cdc.gov/view/cdc/196763/cdc_196763_DS1.pdf
• File Type:
  [PDF - 202.75 KB ]