【摘要】 应用高香草酸荧光分析技术及NADH─高铁氰化钾还原酶法对正常和Graves病甲状腺过氧化氢(H2O2)和NADH─细胞色素b5还原酶(b5R)进行测定， 发现Graves病甲状腺b5R活性和H2O2水平均明显高于正常, 而H2O2酶活性在Graves病和正常甲状腺间无显著差异。加b5R 抑制剂对氯汞苯甲酸后，Graves病和正常甲状腺b5R活性降低近85%，同时H2O2降低50％。b5R活性和H2O2水平两者呈显著正相关关系。以上结果表明b5R参与甲状腺内H2O2的生物合成,是甲状腺内H2O2生成的重要酶系。更多还原

【Abstract】 The activity of NADH-cytochrome b5 reductase (b5R) and the levels of hydrogen peroxide in thyroid of Graves’ disease(GD) an d normol control were measured with potassium ferricyanide as substrate and with the homovanillic acid fluorescence assay. The activity of b5R a nd the levels of H2O2 in GD thyroid were definitely higher than that in no rmal control, but the activity of catalase was not different between GD and normal thyroid. After addition of p-chloromercuribenzonate, a b5R inhibi tor, the activity of b5R in GD and normal thyrioid decreased by 85%, at sam e time the levels of H2O2 decreased by 50%.There was positive correlation between levels of H2O2 and activity of b5R. Our data indicated that b 5R participate in thyroid hy drogen peroxide biosynthesis and is an important emzyme to produce H2O2.更多还原