| Title: | Nonparticulate components of diesel exhaust promote constriction in coronary arteries from ApoE-/- mice |
| Author(s): | Campen MJ; Babu NS; Helms GA; Pett S; Wernly J; Mehran R; McDonald JD; |
| Address: | "Department of Toxicology, Lovelace Respiratory Research Institute, Albuquerque, New Mexico 87108, USA. mcampen@LRRI.org" |
| ISSN/ISBN: | 1096-6080 (Print) 1096-0929 (Linking) |
| Abstract: | "Air pollution is positively associated with increased daily incidence of myocardial infarction and cardiovascular mortality. We hypothesize that air pollutants, primarily vapor phase organic compounds, cause an enhancement of coronary vascular constriction. Such events may predispose susceptible individuals to anginal symptoms and/or exacerbation of infarction. To develop this hypothesis, we studied the effects of nonparticulate diesel exhaust constituents on (1) electrocardiographic traces from ApoE-/- mice exposed whole-body and (2) isolated, pressurized septal coronary arteries from ApoE-/- mice. ApoE-/- mice were implanted with radiotelemetry devices to assess electrocardiogram (ECG) waveforms continuously throughout exposures (6 h/day x 3 days) to diesel exhaust (0.5 and 3.6 mg/m3) in whole-body inhalation chambers with or without particulates filtered. Significant bradycardia and T-wave depression were observed, regardless of the presence of particulates. Pulmonary inflammation was present only in the whole exhaust-exposed animals at the highest concentration. Fresh diesel exhaust or air was bubbled through the physiologic saline tissue bath prior to experiments to enable the isolated tissue exposure; exposed saline contained elevated levels of several volatile carbonyls and alkanes, but low to absent levels of polycyclic aromatic hydrocarbons. Vessels were then assayed for constrictive and dilatory function. Diesel components enhanced the vasoconstrictive effects of endothelin-1 and reduced the dilatory response to sodium nitroprusside. These data demonstrate that nonparticulate compounds in whole diesel exhaust elicit ECG changes consistent with myocardial ischemia. Furthermore, the volatile organic compounds in the vapor phase caused enhanced constriction and reduced dilatation in isolated coronary arteries caused by nonparticulate components of diesel exhaust" |
| Keywords: | "Air Pollutants/*toxicity Animals Bradycardia/chemically induced/physiopathology Coronary Vessels/*drug effects/physiopathology Dose-Response Relationship, Drug Electrocardiography Heart Conduction System/drug effects Heart Rate/drug effects In Vitro Techn;" |
| Notes: | "MedlineCampen, Matthew J Babu, N Sathish Helms, G Andrew Pett, Stuart Wernly, Jorge Mehran, Reza McDonald, Jacob D eng Research Support, U.S. Gov't, Non-P.H.S. 2005/08/12 Toxicol Sci. 2005 Nov; 88(1):95-102. doi: 10.1093/toxsci/kfi283. Epub 2005 Aug 10" |
