Copper and iron complexes catalytic for oxygen radical reactions in sweat from human athletes

Sweat collected from 'explosive' and 'endurance' athletes immediately after exercise contains low molecular mass complexes of copper detectable by their ability to bind to o-phenanthroline. Concentrations of these copper complexes are much greater in arm sweat than in trunk sweat. The iron content of arm sweat, as determined by the ferrozine method, is also greater than that of trunk sweat. However, much of the iron in trunk sweat exists in a low molecular mass form that can bind to the antibiotic bleomycin, whereas the iron in arm sweat does not exist in this form. The metal complexes in human sweat are capable of stimulating the peroxidation of membrane lipids in the presence of ascorbic acid. The physiological significance of the presence of iron and copper complexes in sweat is discussed.