论文部分内容阅读
目的探讨硝基左旋精氨酸甲基酯（Ｌ－ＮＡＭＥ）对小肠上皮细胞辐射防护的机理。方法实验用大鼠ＩＥＣ－６细胞，６０Ｃｏγ射线照射；荧光分光光度法测定培养液上清中一氧化氮（ＮＯ）含量；ＮＡＤＰＨ黄递酶组化法（ＮＤ组化法）和免疫细胞化学法观察一氧化氮合酶（ＮＯＳ）活性变化；ＭＴＴ法检测细胞的生存力。结果ＩＥＣ－６细胞经射线照射后，其培养液上清中ＮＯ含量明显增加，细胞内结构型一氧化氮合酶（ｃＮＯＳ）活性升高，诱导型一氧化氮合酶（ｉＮＯＳ）活性降低，Ｌ－ＮＡＭＥ能明显提高细胞的生存力，ＮＯ底物－左旋精氨酸（Ｌ－Ａｒｇ）部分逆转其作用。结论ＮＯ参与了ＩＥＣ－６细胞的辐射损伤，Ｌ－ＮＡＭＥ对ＩＥＣ－６细胞具有辐射防护作用。
Objective To investigate the mechanism of radioprotection of L-arginine methyl ester (L-NAME) on intestinal epithelial cells. Methods The levels of nitric oxide (NO) in culture supernatants were determined by fluorescence spectrophotometry with rat IEC-6 cells exposed to 60Co γ ray. NADPH diaphorase histochemistry (ND) and immunocytochemistry The changes of nitric oxide synthase (NOS) activity were observed. Cell viability was measured by MTT assay. Results After irradiation of IEC-6 cells, the content of NO in the culture supernatant increased significantly, the activity of cNOS increased, the activity of iNOS decreased, L-NAME significantly increased cell viability, while L-Arginine (L-Arg) partially reversed its effect. Conclusion NO participates in the radiation injury of IEC-6 cells and L-NAME has a radioprotective effect on IEC-6 cells.