NADH-细胞色素b_5还原酶与散发性甲状腺肿的关系

Effect of NADH-cytochrome b_5 reductase in the pathogenesis of sporadic goiter

目的 探讨 NADH-细胞色素 b5 还原酶 (b5 R)在散发性甲状腺肿发病中作用。方法 应用荧光分析等技术测定甲状腺 b5 R活性和 H2 O2 浓度 ,用 b5 R抑制剂观察 b5 R活性变化对 H2 O2 浓度和蛋白结合碘 (PBI)形成影响。结果 甲状腺 H2 O2 浓度和 PBI形成随 b5 R活性降低而减少 ,抑制 b5 R活性可抑制 H2 O2 和 PBI的形成。H2 O2 酶可明显减少 PBI形成 ,而葡萄糖和葡萄糖氧化酶系统可增加 PBI形成。结论 b5 R参与甲状腺 H2 O2 生成 ,b5 R活性缺乏在散发性甲状腺肿发病中可能起重要作用。

Objective To investigate the effect of NADH-cytochrome b_5 reductase (b_5R) in the pathogenesis of sporadic goiter.Methods The activity of b_5R and the levels of H_2O_2 in thyroid were measured with potassium ferricyanide as substrate and with the homovanillic acid fluorescence assay,the effect of change of b_5R activity on the levels of H_2O_2 and formation of protein-bound iodine (PBI) were observed by the addition of b_5R inhibitor.Results The levels of H_2O_2 and PBI formation decreased with b_5R activity decreasing,inhibition of b_5R activity could inhibit generation of H_2O_2 and PBI formation.Catalase reduced PBI formation and glucose/glucose oxidase system increased PBI formation.Conclusions b_5R participates in generation of H_2O_2,deficient b_5R activity may play an important role in pathogenesis of sporadic goiter.