Oshitani N, Kitano A, Okabe H, Nakamura S, Matsumoto T, Kobayashi K
Third Department of Internal Medicine, Osaka City University Medical School, Japan.
Gut. 1993 Jul;34(7):936-8. doi: 10.1136/gut.34.7.936.
To identify which cells generate superoxide, inflamed human mucosa was tested with nitro-blue tetrazolium as a probe, because it is reduced by strong reducing agents to form insoluble blue formazan, which then precipitates in tissues. Biopsy specimens from control subjects and patients with ulcerative colitis were studied. The specimens were organ cultured with bubbling air or nitrogen, and inhibition of the reduction by catalase (a hydrogen peroxide scavenger), para-benzoquinone (a tissue permeable superoxide scavenger), or superoxide dismutase (a superoxide scavenger) was assayed. The dye was reduced by epithelial cells, vascular endothelium, and infiltrating mononuclear cells of the mucosa. Its reduction by vascular endothelium and infiltrating mononuclear cells was greater in inflamed mucosa. The reduction by vascular endothelium and infiltrating mononuclear cells was inhibited in cultures with nitrogen saturation or with 1 mM para-benzoquinone. The vascular endothelium seems to produce superoxide in the inflamed mucosa, which would exacerbate tissue injury in ulcerative colitis.
为了确定哪些细胞产生超氧化物，以硝基蓝四唑作为探针检测炎症状态下的人体黏膜，因为它可被强还原剂还原形成不溶性蓝色甲臜，然后沉淀在组织中。研究了来自对照受试者和溃疡性结肠炎患者的活检标本。将标本在通入空气或氮气的条件下进行器官培养，并检测过氧化氢酶（一种过氧化氢清除剂）、对苯醌（一种可透过组织的超氧化物清除剂）或超氧化物歧化酶（一种超氧化物清除剂）对还原反应的抑制作用。染料可被黏膜的上皮细胞、血管内皮细胞和浸润的单核细胞还原。在炎症黏膜中，血管内皮细胞和浸润的单核细胞对染料的还原作用更强。在氮气饱和或加入1 mM对苯醌的培养物中，血管内皮细胞和浸润的单核细胞对染料的还原作用受到抑制。血管内皮细胞似乎在炎症黏膜中产生超氧化物，这会加剧溃疡性结肠炎中的组织损伤。
