Five automated 5-h animal exposures were performed that produced controlled and consistent
COREXIT EC9500A concentrations (27.1 +/- 2.9 mg/m(3), mean +/- SD).”
“COREXIT EC9500A (COREXIT) was used to disperse crude oil during the 2010 Deepwater Horizon oil spill. While the environmental impact of COREXIT has been examined, the pulmonary effects click here are unknown. Investigations were undertaken to determine whether inhaled COREXIT elicits airway inflammation, alters pulmonary function or airway reactivity, or exerts pharmacological effects. Male rats were exposed to COREXIT (mean 27 mg/m(3), 5 h). Bronchoalveolar lavage was performed on d 1 and 7 postexposure. Lactate dehydrogenase (LDH) and
albumin were measured as indices of lung injury; macrophages, neutrophils, lymphocytes, and eosinophils were quantified to evaluate inflammation; and oxidant production by macrophages and neutrophils was measured. There were no significant effects of COREXIT on LDH, albumin, inflammatory cell levels or oxidant production at either time point. In conscious animals, neither breathing frequency nor specific airway resistance were altered at 1 hr, 1 d and 7 d postexposure. Airway resistance responses to methacholine (MCh) aerosol in anesthetized animals were unaffected at 1 and 7 d postexposure, while dynamic compliance responses were decreased after 1 d but not 7 d. In tracheal strips, in the presence or absence of MCh, low concentrations of COREXIT (0.001% A-1210477 v/v) elicited relaxation; contraction occurred at 0.003-0.1% v/v. In isolated, perfused trachea,
intraluminally applied COREXIT produced similar effects but at higher concentrations. COREXIT inhibited neurogenic contractile responses of strips to electrical field stimulation. Our findings suggest that COREXIT inhalation did not initiate lung inflammation, but may transiently next increase the difficulty of breathing.”
“These studies characterized cardiovascular responses after an acute inhalation exposure to COREXIT EC9500A, the oil dispersant used in the Deepwater Horizon oil spill. Male Sprague-Dawley rats underwent a single 5-h inhalation exposure to COREXIT EC9500A (average exposure level 27.12 mg/m(3)) or air. On d 1 and 7 following the exposure, rats were implanted with indwelling catheters and changes in heart rate and blood pressure were assessed in response to increasing levels of adrenoreceptor agonists. A separate group of rats was euthanized at the same time points, ventral tail arteries were dissected, and vascular tone along with dose-dependent responses to vasoconstricting and dilating factors were assessed in vitro. Agonist-induced dose-dependent increases in heart rate and blood pressure were greater in COREXIT EC9500A-exposed than in air-exposed rats at 1 d but not 7 d after the exposure.