title: Electron paramagnetic resonance spectroscopic evidence of increased free radical generation and selective damage to skeletal muscle following lightning injury.
abstract: The present case study examined changes in peripheral markers of free radical metabolism and skeletal/myocardial muscle damage 30 h after a mountaineer had survived a lightning storm, having experienced contact with what was considered to be "upward leaders" at 4200 m. Sea-level control data were available between 3 and 8 weeks prior to the altitude sojourn for comparative purposes. Follow-up measurements were obtained for the same individual 3 weeks following the incident after simulated exposure to the combined stresses of inspiratory hypoxia and physical exercise. Venous blood was assayed for molecular markers of skeletal [myoglobin and total creatine phosphokinase (CPK)] and myocardial [cardiac troponin I (cTnI)] muscle damage. Ex-vivo spin trapping with alpha-phenyl-tert-butylnitrone (PBN) combined with electron paramagnetic resonance (EPR) spectroscopy was incorporated for the direct detection of free radicals. The relative increases [post-exposure/preexposure x 100 (%)] in the concentration of the PBN adduct, myoglobin, and CPK in the "lightning blood" were markedly greater than those observed following the simulation study (PBN: 276 vs. 129%; CPK: 1130 vs. 182%; myoglobin: 205 vs. 115%). In contrast, no changes were observed for cTnI. A marked decrease in the PBN adduct, myoglobin, and CPK was observed within 2 h of completing the simulation study, following oral administration of water and lipid-soluble antioxidant vitamins in normoxia. These findings are the first to document lightning-induced free radical generation and selective damage to skeletal muscle in a high altitude mountaineer. Furthermore, free radicals may contribute to the pathogenesis of lightning injury, and dietary supplementation with antioxidant vitamins may prove of some benefit against associated tissue damage.
authors.affiliation: Hypoxia Research Unit, Department of Physiology, School of Applied Sciences, University of Glamorgan, South Wales, UK CF37 1DL. dbailey1@glam.ac.uk
authors.forename: Damian M
authors.initials: DM
authors.lastname: Bailey
authors.forename: Peter
authors.initials: P
authors.lastname: Bärtsch
authors.forename: Mary Ann
authors.initials: MA
authors.lastname: Cooper
mesh_terms: D000328:Adult; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals / Q000378:metabolism*; D006230:Hand Injuries / Q000150:complications; D006801:Humans; D015168:Lightning Injuries / Q000150:complications* / Q000378:metabolism*; D008297:Male; D009051:Mountaineering / Q000293:injuries; D018482:Muscle, Skeletal / Q000293:injuries*
chemical_list: D005609:Free Radicals