Abstract 20621: Longitudinal Detection of ROS Production in Balloon-Injured Arteries by Bioluminescence Imaging
Background: Increased levels of reactive oxygen species (ROS) in vascular tissue play a central role in the pathogenesis of atherosclerosis, restenosis and hypertension. Conventionally ROS detection in the experimental models of vascular disease is accomplished by chemoluminescence techniques or by oxidative fluorescent microtopography. Both methods use blood vessels explanted from animals and thus are incompatible with longitudinal assessment of ROS production in vivo. In this study we validated an optical imaging protocol for the intravital detection of vascular ROS production and examined a time course of ROS accumulation in balloon-injured rat carotid arteries.
Methods: Vascular oxidative stress was induced in rat carotid arteries (n=4) using Fogarty balloon-catheter injury. A time course of ROS production was assessed at days 0, 1, 3, 7 and 14 after vascular trauma by bioluminescence imaging (IVIS Spectrum) using a 10-min local saturation of carotid artery with a 4 mM solution of a ROS indicator, L-012. The specificity of the luminescence signal was assessed by the preincubation with a ROS inducer, PDBu, and a ROS inhibitor, Mn(III)TMPyP.
Results: No measurable signal was emitted by non-injured rat carotids. Balloon injury resulted in 117-, 20-, 8- and 3-fold increase of vascular ROS at days 1, 3, 7 and 14 post-injury, respectively, in comparison with the baseline. Importantly, PDBu and Mn(III)TMPyP pretreatments resulted in a 300% increase and a 82% decrease of ROS-induced luminescence in injured rat arteries, respectively, thus validating the causative role of ROS as the source of observed vascular luminescence.
Conclusions: 1) Bioluminescence optical imaging allows longitudinal monitoring of ROS activity in the vasculature of living animals. 2) A standard model of vascular injury, Fogarty balloon denudation of rat carotid arteries results in rapid accumulation of ROS in injured arteries with gradual normalization of ROS levels by 14 days post-injury.
- © 2010 by American Heart Association, Inc.