Kimura H, Hokari R, Miura S, Shigematsu T, Hirokawa M, Akiba Y, Kurose I, Higuchi H, Fujimori H, Tsuzuki Y, Serizawa H, Ishii H
Department of Internal Medicine, School of Medicine, Keio University, Tokyo, 160, Japan.
Gut. 1998 Feb;42(2):180-7. doi: 10.1136/gut.42.2.180.
Increased production of reactive metabolites of oxygen and nitrogen has been implicated in chronic inflammation of the gut. The object of this study was to examine the magnitude and location of nitric oxide synthase (NOS) activity and peroxynitrite formation in the colonic mucosa of patients with ulcerative colitis in relation to the degree of inflammation.
Thirty three patients with active ulcerative colitis (17 with mild or moderate inflammation, 16 with severe inflammation).
Inducible NOS activity was determined in the colonic mucosa by measuring the conversion of L-arginine to citrulline in the absence of calcium. The localisation of NOS and nitrotyrosine immunoreactivity was assessed immunohistochemically using the labelled streptavidin biotin method.
Inducible NOS activity increased in parallel with the degree of inflammation of the mucosa. Expression of inducible NOS was found not only in the lamina propria, but also in the surface of the epithelium. Peroxynitrite formation as assessed by nitrotyrosine staining was frequently observed in the lamina propria of actively inflamed mucosa.
Nitric oxide and peroxynitrite formation may play an important role in causing irreversible cellular injury to the colonic mucosa in patients with active ulcerative colitis.
氧和氮的反应性代谢产物生成增加与肠道慢性炎症有关。本研究的目的是检测溃疡性结肠炎患者结肠黏膜中一氧化氮合酶（NOS）活性和过氧亚硝酸盐形成的程度及位置，并探讨其与炎症程度的关系。
33例活动期溃疡性结肠炎患者（17例轻度或中度炎症，16例重度炎症）。
通过测量无钙条件下L-精氨酸向瓜氨酸的转化来测定结肠黏膜中的诱导型NOS活性。采用标记链霉亲和素生物素法免疫组化评估NOS和硝基酪氨酸免疫反应性的定位。
诱导型NOS活性与黏膜炎症程度平行增加。诱导型NOS不仅在固有层表达，也在上皮表面表达。通过硝基酪氨酸染色评估，过氧亚硝酸盐形成在活动期炎症黏膜的固有层中经常观察到。
一氧化氮和过氧亚硝酸盐的形成可能在活动期溃疡性结肠炎患者结肠黏膜不可逆细胞损伤中起重要作用。
