抄録
Activities, contents and true specific activities of superoxide dismutase (SOD) were determined in the erythrocytes of 105 normal human subjects. The mean SOD activity assayed by xanthine autoxidation inhibition was 11.0×103units/gHb, and the mean content assayed by immunochemical method was 456μg/gHb. Both SOD activity and content followed normal distributions and no significant variations with regard to sex and age were detected. A highly positive correlation between SOD activities and contents was observed in normal subjects (r=0.77, p<0.001). With 0.1mM KCN approximately 90% of SOD activity was inhibited, while its content was unaffected by the present method. True specific activity was calculated from activity and content levels. The true mean specific activity in human erythrocytes was 23.7units/μg SOD. In this case, there was no significant difference regard to the aging. In this paper, the relationships between SOD activity and content are discussed and the availability of true specific activity of SOD in human erythrocytes is considered.