Luminol assay for microdetermination of superoxide dismutase activity: its application to human fetal blood.
A microtechnique for determining the superoxide dismutase activity in erythrocytes is described. This technique involves the inhibition of luminol-enhanced chemiluminescence of superoxide anion generated by xanthine-xanthine oxidase. Measurements required a steady-state chemiluminescence whether superoxide dismutase was present or absent; the level of luminescence was correlated to enzyme activity. Superoxide dismutase activity measured by this technique was 836 +/- 112 micrograms/g of hemoglobin for whole blood and 834 +/- 109 micrograms/g of hemoglobin for erythrocytes. When the reference technique was applied to larger amounts of blood, the results were 862 +/- 58 and 858 +/- 116 micrograms/g of hemoglobin for whole blood and washed erythrocytes, respectively. The enzymatic activity of superoxide dismutase from fetal blood (obtained by venipuncture in utero and of 19-26 weeks gestational age) was similar to that of adult blood, when measured by the new technique.
D000328:Adult; D004912:Erythrocytes / Q000201:enzymology; D005260:Female; D005312:Fetal Blood / Q000201:enzymology*; D006801:Humans; D007700:Kinetics; D008163:Luminescent Measurements; D008165:Luminol; D008832:Microchemistry; D011247:Pregnancy; D013482:Superoxide Dismutase / Q000097:blood*; D019820:Xanthine; D014969:Xanthine Oxidase; D014970:Xanthines
D014970:Xanthines; D019820:Xanthine; D008165:Luminol; D013482:Superoxide Dismutase; D014969:Xanthine Oxidase