[Protein status and antioxidant capability of residents in endemic and nonendemic areas of Keshan disease(KD)].

From a survey of residents in endemic and nonendemic areas of Keshan disease(KD), it was found that the plasma cystine, tryptophan and lysine as well as blood selenium content were lower, while the plasma lipid peroxide was higher in endemic areas than those in non-endemic areas. These results suggests that the selenium deficiency coexisting with cystine and tryptophan insufficiency decreases the antioxidant defense of the organism and may be one of the important factors for the development of KD. The role of sulfur-containing amino acid in antioxidant defense is discussed emphatically.