文章基本信息

标题：Dobutamine “Stress” Test and Latent Cardiac Susceptibility to Inhaled Diesel Exhaust in Normal and Hypertensive Rats
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作者：Mehdi S. Hazari ; Justin Callaway ; Darrell W. Winsett 等
期刊名称：Environmental Health Perspectives
印刷版ISSN：0091-6765
电子版ISSN：1552-9924
出版年度：2012
卷号：120
期号：8
页码：1088-1093
DOI：10.1289/ehp.1104684
出版社：OCR Subscription Services Inc
摘要：Ba c k g r o u n d: Exercise "stress" testing is a screening tool used to determine the amount of stress for which the heart can compensate before developing abnormal rhythm or ischemia, particularly in susceptible persons. Although this approach has been used to assess risk in humans exposed to air pollution, it has never been applied to rodent studies.oB j e c t i v e: We hypothesized that a single exposure to diesel exhaust (DE) would increase the risk of adverse cardiac events such as arrhythmia and myocardial ischemia in rats undergoing a dobuta mine challenge test, which can be used to mimic exercise-like stress.Me t h o d s: Wistar-Kyoto normotensive (WKY) and spontaneously hypertensive (SH) rats implanted with radiotelemeters and a chronic intravenous catheter were whole-body exposed to 150 μg/m3DE for 4 hr. Increasing doses of dobuta mine, a b1-adrenergic agonist, were administered to conscious unrestrained rats 24 hr later to elicit the cardiac response observed during exercise while heart rate (HR) and electrocardiogram (ECG) were monitored.re s u l t s: A single exposure to DE potentiated the HR response of WKY and SH rats during dobuta mine challenge and prevented HR recovery at rest. During peak challenge, DE-exposed SH rats had lower overall HR variability when compared with controls, in addition to transient ST depression. All DE-exposed animals also had increased arrhythmias.co n c l u s i o n s: These results are the first evidence that rats exhibit stress-induced cardiac dysrhyth-mia and ischemia sensitivity comparable to humans after a single exposure to a toxic air pollutant, particularly when in the presence of underlying cardio vascular disease. Thus, exposure to low con-centrations of air pollution can impair the heart's ability to respond to stress and increase the risk of subsequent triggered dysfunction
关键词：air pollution; arrhythmia; cardiac; diesel exhaust; dobuta ;mine; "stress" test