Acute effects of COREXIT® EC9500A on cardiovascular function

Abstract

The goal of these studies was to characterize cardiovascular responses after an acute inhalation exposure to COREXIT® EC9500A, the oil dispersant used in the Deepwater Horizon oil spill response. Male Sprague Dawley rats underwent a single 5 h exposure to COREXIT® EC9500A (N= 5 exposures, average exposure level 27.12 mg/m3) or air. On days 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. Separate groups of rats were 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 where greater in COREXIT® EC9500A than air exposed rats 1 but not 7 days after the exposure. COREXIT® EC9500A exposure also induced an increase in basal tone and a reduced responsiveness of tail arteries to acetylcholine‐mediated vasodilation 1 day following the exposure. These findings demonstrate that an acute exposure to COREXIT® EC9500A had transient effects on cardiovascular and peripheral vascular function.