Racial Differences in Free Radical Scavenging Enzyme Activity in Children

Abstract

Oxygen-derived free radicals play an important role in multiple pediatric neurologic diseases. Five intracellular free radical scavenging enzymes and three trace elements provide a significant portion of the body's defenses against 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 determine the effect of racial differences on the activity of five free radical scavenging enzymes and the concentrations of three associated trace elements in normal, healthy American children. The erythrocyte and plasma activities of five major free radical scavenging enzymes (glutathione peroxidase, glutathione reductase, glutathione-S-transferase, catalase, and superoxide dismutase) and plasma concentrations of three associated trace elements (selenium, copper, and zinc) were determined for 83 healthy American children, 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 erythrocyte glutathione peroxidase activity, erythrocyte superoxide dismutase 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 higher activity in the two most important free radical scavenging enzymes used by the brain compared to age- and sex-matched Caucasian children. Future clinical research in free radical-mediated pediatric neurologic diseases needs to consider race along with age and sex in both study design and data analysis.

Relationship of antioxidant enzyme activities with myelomeningocele

“…All infants with MM had deficiencies in erythrocyte FRSE activities. The differences identified in FRSE activities were consistent with the results indicated in the literature (6,7,10,12). Graff et al (7) found that there were significant differences between patient and control groups.…”

“…Only a few articles describing abnormal FRSE activities in infants with MM have been published (6,7,8,10). Previous studies measured FRSE activities, especially GSH-related reported a similar observation.…”

“…Oxygen-derived FRs are important factors in the pathogenesis of many pediatric neurological diseases (6,7,10,24). Numerous studies have shown the relationship between FRs and neural tube defects (7, 8, 9, 10, 20, 29).…”

“…The impaired responsiveness of the FRSE system plays a crucial role in oxygen-induced embryopathy and might result in MM (7,8,9,10,12,15,21). Erythrocyte FRSE are the most important enzymes in prevention of FRmediated neurological disease (6). When FR damage occurs, cellular repair systems such as GPX and GST can restore cellular components to their normal structure and function (21).…”

Selenium status and associated factors in a British National Diet and Nutrition Survey: young people aged 4–18 y

“…To the authors' knowledge there is little published information about socio-economic determinants of Se status. Likewise, apart from recent evidence of higher plasma Se concentration and RBC GPx activity in a small number of AfricanAmerican children compared with their Caucasian counterparts (Glauser et al, 1999), ethnic differences in Se status indices appear not to have been reported elsewhere (Alfthan & Nève, 1996). It seems unlikely that the non-Caucasians, Selenium status in young people CJ Bates et al who had higher plasma and RBC Se concentrations (Table 7), also had higher Se intake than the Caucasians.…”