Plasma antioxidants and lipid peroxidation products in Duchenne muscular dystrophy.

Lipid peroxidation (LPX) products in plasma were elevated in Duchenne muscular dystrophy (DMD) patients (n = 9) compared with an age- and sex-matched group of controls (n = 10). Trichloroacetic acid-precipitable thiobarbituric acid-reactive substances (TBARS) were increased by 35% (p less than 0.01), conjugated dienes by 77% (p less than 0.02) and fluorescent pigments (FP) by 70% (p less than 0.001). Plasma alpha-tocopherol was significantly decreased, by 50%, in DMD compared with healthy subjects (p less than 0.002). In conjunction with the finding of others of a deficiency in DMD of the plasma lipoproteins which normally transport vitamin E to the tissues, this may contribute to the increased LPX seen in the disease especially if muscle damage also liberates free Fe2+. The major circulating antioxidant protein, caeruloplasmin (CP), was significantly increased (p less than 0.001) by 25-30% in DMD patients compared with both adult and young male controls. In DMD patients only, this increase is correlated with the concentration of TBARS and FP suggesting that increased LPX may be a trigger for CP synthesis.