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.