title: Whole body plethysmography reveals differential ventilatory responses to ozone in rat models of cardiovascular disease.
abstract: To elucidate key factors of host susceptibility to air pollution, healthy and cardiovascular (CV)-compromised rats were exposed to air or ozone (O3) at 0.25, 0.5, or 1.0 ppm for 4 h. We hypothesized that rat strains with the least cardiac reserve would be most prone to develop significant health effects. Using flow whole body plethysmography (FWBP), ventilatory responses in healthy 3-month-old male rats [i.e. Wistar-Kyoto (WKY), Wistar (WIS), and Sprague-Dawley (SD) strains] were compared with hypertensive [i.e. spontaneously hypertensive (SH), fawn-hooded-hypertensive (FHH), and SH-stroke-prone (SHSP)] strains and obese [i.e. SH-heart failure-prone (SHHF) and JCR:LA-cp, atherosclerosis-prone (JCR)] strains. SH were slower to acclimate to the FWBP chambers. At 0-h post-air-exposure, SHSP and SHHF exhibited hyperpnea, indicative of cardiopulmonary insufficiency. At 0-h-post-O3, all but one strain showed significant concentration-dependent decreases in minute volume [MV = tidal volume (TV) × breathing frequency]. Comparing air with 1.0 ppm responses, MV declined 20-27% in healthy, 21-42% in hypertensive, and 33% in JCR rats, but was unchanged in SHHF rats. Penh increased significantly in all strains, with disproportionate increases in "responder" WKY and FHH strains. By 20 h, most changes had resolved, although Penh remained elevated in WKY, SH, and SHSP. Based on the effective dose estimates (O3 ppm × h × MV), the most CV-compromised (SHSP and SHHF) strains received significantly greater O3 lung deposition (25% and 40%, respectively). Data support epidemiologic associations that individuals with cardiopulmonary insufficiency are at greater risk for urban pollutant exposure due, in part, to enhanced lung deposition and exacerbation of hypoxia and pathophysiologic processes of heart failure.
authors.affiliation: a Environmental Public Health Division, NHEERL, U.S. Environmental Protection Agency , Research Triangle Park , NC , USA and.
authors.forename: Janice A
authors.initials: JA
authors.lastname: Dye
authors.affiliation: a Environmental Public Health Division, NHEERL, U.S. Environmental Protection Agency , Research Triangle Park , NC , USA and.
authors.forename: Allen D
authors.initials: AD
authors.lastname: Ledbetter
authors.affiliation: a Environmental Public Health Division, NHEERL, U.S. Environmental Protection Agency , Research Triangle Park , NC , USA and.
authors.forename: Mette C
authors.initials: MC
authors.lastname: Schladweiler
authors.affiliation: b National Program for Air Climate & Energy Research, Office of Research and Development, US Environmental Protection Agency , Research Triangle Park , NC , USA.
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Costa
authors.affiliation: a Environmental Public Health Division, NHEERL, U.S. Environmental Protection Agency , Research Triangle Park , NC , USA and.
authors.forename: Urmila P
authors.initials: UP
authors.lastname: Kodavanti
mesh_terms: D000393:Air Pollutants / Q000009:adverse effects; D000818:Animals; D001835:Body Weight; D019570:Inhalation Exposure; D008297:Male; D010126:Ozone / Q000009:adverse effects*; D010993:Plethysmography, Whole Body; D051381:Rats; D011919:Rats, Inbred Strains; D012119:Respiration / Q000187:drug effects*
chemical_list: D000393:Air Pollutants; D010126:Ozone
keywords: Cardiovascular disease models; ozone; rat; ventilatory parameters; whole body plethysmography