title: Comparative electrocardiographic, autonomic and systemic inflammatory responses to soy biodiesel and petroleum diesel emissions in rats.
abstract: BACKGROUND
  Biodiesel fuel represents an alternative to high particulate matter (PM)-emitting petroleum-based diesel fuels, yet uncertainty remains regarding potential biodiesel combustion emission health impacts.
  
  
  OBJECTIVE
  The purpose of this study was to compare cardiovascular responses to pure and blended biodiesel fuel emissions relative to petroleum diesel exhaust (DE).
  
  
  METHODS
  Spontaneously hypertensive rats were exposed for 4 h per day for four days via whole body inhalation to combustion emissions (based on PM concentrations 50, 150 or 500 μg/m(3) or filtered air) from pure (B100) or blended (B20) soy biodiesel, or to pure petroleum DE (B0). Electrocardiogram (ECG) and heart rate variability (HRV, an index of autonomic balance) were monitored before, during and after exposure while pulmonary and systemic inflammation were assessed one day after the final exposure. ECG and HRV data and inflammatory data were statistically analyzed using a linear mixed model for repeated measures and an analysis of variance, respectively.
  
  
  RESULTS
  B100 and B0, but not B20, increased HRV during all exposure days at the highest concentration indicating increased parasympathetic tone. Electrocardiographic data were mixed. B100 and B0, but not B20, caused significant changes in one or more of the following: serum C-reactive protein, total protein, low density lipoprotein (LDL) and high density lipoprotein (HDL) cholesterol, and blood urea nitrogen (BUN) and plasma angiotensin converting enzyme (ACE) and fibrinogen.
  
  
  CONCLUSIONS
  Although responses to emissions from all fuels were mixed and relatively mild, some findings point to a reduced cardiovascular impact of blended biodiesel fuel emissions.
authors.affiliation: a Environmental Public Health Division, NHEERL, US Environmental Protection Agency , Research Triangle Park , NC , USA.
authors.forename: A K
authors.initials: AK
authors.lastname: Farraj
authors.affiliation: a Environmental Public Health Division, NHEERL, US Environmental Protection Agency , Research Triangle Park , NC , USA.
authors.forename: N
authors.initials: N
authors.lastname: Haykal-Coates
authors.affiliation: a Environmental Public Health Division, NHEERL, US Environmental Protection Agency , Research Triangle Park , NC , USA.
authors.forename: D W
authors.initials: DW
authors.lastname: Winsett
authors.affiliation: a Environmental Public Health Division, NHEERL, US Environmental Protection Agency , Research Triangle Park , NC , USA.
authors.forename: M I
authors.initials: MI
authors.lastname: Gilmour
authors.affiliation: a Environmental Public Health Division, NHEERL, US Environmental Protection Agency , Research Triangle Park , NC , USA.
authors.forename: C
authors.initials: C
authors.lastname: King
authors.affiliation: a Environmental Public Health Division, NHEERL, US Environmental Protection Agency , Research Triangle Park , NC , USA.
authors.forename: Q T
authors.initials: QT
authors.lastname: Krantz
authors.affiliation: a Environmental Public Health Division, NHEERL, US Environmental Protection Agency , Research Triangle Park , NC , USA.
authors.forename: J
authors.initials: J
authors.lastname: Richards
authors.affiliation: a Environmental Public Health Division, NHEERL, US Environmental Protection Agency , Research Triangle Park , NC , USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Hazari
mesh_terms: D000818:Animals; D001341:Autonomic Nervous System / Q000187:drug effects / Q000378:metabolism; D056804:Biofuels / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004562:Electrocardiography / Q000187:drug effects* / Q000379:methods; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D018836:Inflammation Mediators / Q000378:metabolism*; D019570:Inhalation Exposure / Q000009:adverse effects; D008297:Male; D052638:Particulate Matter / Q000633:toxicity; D010578:Petroleum / Q000633:toxicity*; D051381:Rats; D011918:Rats, Inbred SHR; D013025:Glycine max / Q000633:toxicity*; D001335:Vehicle Emissions / Q000633:toxicity*
chemical_list: D056804:Biofuels; D018836:Inflammation Mediators; D052638:Particulate Matter; D010578:Petroleum; D001335:Vehicle Emissions
keywords: Autonomic; biodiesel; cardiovascular; diesel; electrocardiogram; inflammatory; petroleum; soy