Absence of modifications of the enzyme defense system against oxygen toxicity in cystic fibrosis.

Cystic fibrosis (CF) has recently been linked to the group of human diseases in which cultured fibroblasts express premature aging. As the deleterious effect of oxygen derivatives in the cell is one of the numerous pathways associated with cell aging, the activity of the enzymatic defense system, superoxide dismutase (SOD), glutathione peroxidase (GSHPx), glutathione reductase (GR), was examined in the erythrocytes of 12 CF children and was compared to age-matched normal controls. No significant differences were found in CF children when compared to the controls. Glutathione-S-transferase was also assayed, but the significant difference found between CF children and normal controls is probably not specific of CF as it is found in other pathologic situations such as hyperbilirubinemia or renal insufficiency.