Pulmonary exposure to peat smoke extracts in rats decreases expiratory time and increases left heart end systolic volume.

Pulmonary exposure to peat smoke extracts in rats decreases expiratory time and increases left heart end systolic volume. Inhal Toxicol. 2019 Jan 15;:1-9 Authors: Thompson LC, Kim YH, Martin BL, Ledbetter AD, Dye JA, Hazari MS, Gilmour MI, Farraj AK Abstract Exposure to wildland fire-related particulate matter (PM) causes adverse health outcomes. However, the impacts of specific biomass sources remain unclear. The purpose of this study was to investigate cardiopulmonary responses in rats following exposure to PM extracts collected from peat fire smoke. We hypothesized that peat smoke PM would dose-dependently alter cardiopulmonary function. Male Sprague-Dawley rats (n = 8/group) were exposed to 35 µg (Lo PM) or 350 µg (Hi PM) of peat smoke PM extracts suspended in saline, or saline alone (Vehicle) via oropharyngeal aspiration (OA). Ventilatory expiration times, measured in whole-body plethysmographs immediately after OA, were the lowest in Hi PM exposed subjects at 6 min into recovery (p = .01 vs. Lo PM, p = .08 vs. Vehicle) and resolved shortly afterwards. The next day, we evaluated cardiovascular function in the same subjects via cardiac ultrasound under isoflurane anesthesia. Compared to Vehicle, Hi PM had 45% higher end systolic volume (p = .03) and 17% higher pulmonary artery blood flow acceleration/ejection time ratios, and both endpoints expressed significant increasing linear trends by dose (p = .0...
Source: Inhalation Toxicology - Category: Respiratory Medicine Tags: Inhal Toxicol Source Type: research