title: Cardiovascular depression in rats exposed to inhaled particulate matter and ozone: effects of diet-induced metabolic syndrome.
abstract: BACKGROUND
  High ambient levels of ozone (O3) and fine particulate matter (PM2.5) are associated with cardiovascular morbidity and mortality, especially in people with preexisting cardiopulmonary diseases. Enhanced susceptibility to the toxicity of air pollutants may include individuals with metabolic syndrome (MetS).
  
  
  OBJECTIVE
  We tested the hypothesis that cardiovascular responses to O3 and PM2.5 will be enhanced in rats with diet-induced MetS.
  
  
  METHODS
  Male Sprague-Dawley rats were fed a high-fructose diet (HFrD) to induce MetS and then exposed to O3, concentrated ambient PM2.5, or the combination of O3 plus PM2.5 for 9 days. Data related to heart rate (HR), HR variability (HRV), and blood pressure (BP) were collected.
  
  
  RESULTS
  Consistent with MetS, HFrD rats were hypertensive and insulin resistant, and had elevated fasting levels of blood glucose and triglycerides. Decreases in HR and BP, which were found in all exposure groups, were greater and more persistent in HFrD rats compared with those fed a normal diet (ND). Coexposure to O3 plus PM2.5 induced acute drops in HR and BP in all rats, but only ND rats adapted after 2 days. HFrD rats had little exposure-related changes in HRV, whereas ND rats had increased HRV during O3 exposure, modest decreases with PM2.5, and dramatic decreases during O3 plus PM2.5 coexposures.
  
  
  CONCLUSIONS
  Cardiovascular depression in O3- and PM2.5-exposed rats was enhanced and prolonged in rats with HFrD-induced MetS. These results in rodents suggest that people with MetS may be prone to similar exaggerated BP and HR responses to inhaled air pollutants.
authors.affiliation: Department of Pathobiology and Diagnostic Investigation, and.
authors.forename: James G
authors.initials: JG
authors.lastname: Wagner
authors.forename: Katryn
authors.initials: K
authors.lastname: Allen
authors.forename: Hui-yu
authors.initials: HY
authors.lastname: Yang
authors.forename: Bin
authors.initials: B
authors.lastname: Nan
authors.forename: Masako
authors.initials: M
authors.lastname: Morishita
authors.forename: Bhramar
authors.initials: B
authors.lastname: Mukherjee
authors.forename: J Timothy
authors.initials: JT
authors.lastname: Dvonch
authors.forename: Catherine
authors.initials: C
authors.lastname: Spino
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Fink
authors.forename: Sanjay
authors.initials: S
authors.lastname: Rajagopalan
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Sun
authors.forename: Robert D
authors.initials: RD
authors.lastname: Brook
authors.forename: Jack R
authors.initials: JR
authors.lastname: Harkema
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002318:Cardiovascular Diseases / Q000139:chemically induced*; D004784:Environmental Monitoring; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D024821:Metabolic Syndrome / Q000209:etiology*; D010126:Ozone / Q000633:toxicity*; D052638:Particulate Matter / Q000633:toxicity*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D052638:Particulate Matter; D010126:Ozone