title: Cellular and subcellular oxidative stress parameters following severe spinal cord injury.
abstract: The present study undertook a comprehensive assessment of the acute biochemical oxidative stress parameters in both cellular and, notably, mitochondrial isolates following severe upper lumbar contusion spinal cord injury (SCI) in adult female Sprague Dawley rats. At 24h post-injury, spinal cord tissue homogenate and mitochondrial fractions were isolated concurrently and assessed for glutathione (GSH) content and production of nitric oxide (NO(•)), in addition to the presence of oxidative stress markers 3-nitrotyrosine (3-NT), protein carbonyl (PC), 4-hydroxynonenal (4-HNE) and lipid peroxidation (LPO). Moreover, we assessed production of superoxide (O2(•-)) and hydrogen peroxide (H2O2) in mitochondrial fractions. Quantitative biochemical analyses showed that compared to sham, SCI significantly lowered GSH content accompanied by increased NO(•) production in both cellular and mitochondrial fractions. SCI also resulted in increased O2(•-) and H2O2 levels in mitochondrial fractions. Western blot analysis further showed that reactive oxygen/nitrogen species (ROS/RNS) mediated PC and 3-NT production were significantly higher in both fractions after SCI. Conversely, neither 4-HNE levels nor LPO formation were increased at 24h after injury in either tissue homogenate or mitochondrial fractions. These results indicate that by 24h post-injury ROS-induced protein oxidation is more prominent compared to lipid oxidation, indicating a critical temporal distinction in secondary pathophysiology that is critical in designing therapeutic approaches to mitigate consequences of oxidative stress.
authors.affiliation: Spinal Cord and Brain Injury Research Center, Department of Physiology, University of Kentucky, Lexington, KY 40536-0509, USA.
authors.forename: Nishant P
authors.initials: NP
authors.lastname: Visavadiya
authors.affiliation: Spinal Cord and Brain Injury Research Center, Department of Physiology, University of Kentucky, Lexington, KY 40536-0509, USA. Electronic address: skpate2@uky.edu.
authors.forename: Samir P
authors.initials: SP
authors.lastname: Patel
authors.affiliation: Spinal Cord and Brain Injury Research Center, Department of Physiology, University of Kentucky, Lexington, KY 40536-0509, USA.
authors.forename: Jenna L
authors.initials: JL
authors.lastname: VanRooyen
authors.affiliation: Spinal Cord and Brain Injury Research Center, Department of Anatomy & Neurobiology, University of Kentucky, Lexington, KY 40536-0509, USA.
authors.forename: Patrick G
authors.initials: PG
authors.lastname: Sullivan
authors.affiliation: Spinal Cord and Brain Injury Research Center, Department of Physiology, University of Kentucky, Lexington, KY 40536-0509, USA.
authors.forename: Alexander G
authors.initials: AG
authors.lastname: Rabchevsky
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D015415:Biomarkers; D005260:Female; D005978:Glutathione / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D015227:Lipid Peroxidation; D008928:Mitochondria / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D050050:Protein Carbonylation; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D013119:Spinal Cord Injuries / Q000378:metabolism* / Q000473:pathology*
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D017382:Reactive Oxygen Species; D009569:Nitric Oxide; D006861:Hydrogen Peroxide; D005978:Glutathione
keywords: 3-Nitrotyrosine; 4-Hydroxynonenal; Mitochondria; Protein carbonyl; RNS; ROS