Racial differences in free radical scavenging enzyme activity in children

Oxygen-derived free radicals play an important role in multiple pediatric n eurologic diseases. Five intracellular free radical scavenging enzymes and three trace elements provide a significant portion of the body's defenses a gainst free radical-mediated injury. Although the effects of age, sex, and ethnicity on the body's antioxidant defenses have been described, no study has examined whether racial differences exist. This pilot study sought to d etermine the effect of racial differences on the activity of five free radi cal scavenging enzymes and the concentrations of three associated trace ele ments in normal, healthy American children. The erythrocyte and plasma acti vities of five major free radical scavenging enzymes (glutathione peroxidas e, glutathione reductase, glutathione-S-transferase, catalase, and superoxi de dismutase) and plasma concentrations of three associated trace elements (selenium, copper, and zinc) were determined for 83 healthy American childr en, aged 1 to 18 years. One- and two-way interactions of race, age, and sex with each dependent variable were analyzed. African-Americans had higher e rythrocyte glutathione peroxidase activity, erythrocyte superoxide dismutas e activity, and selenium and copper concentrations than Caucasians. Racial inequalities do exist in free radical scavenging enzyme activity and trace element concentration in healthy children. African-American children had hi gher activity in the two most important free radical scavenging enzymes use d by the brain compared to age- and sex-matched Caucasian children. Future clinical research in free radical-mediated pediatric neurologic diseases ne eds to consider race along with age and sex in both study design and data a nalysis.