中文摘要：

背景：一氧化氮可通过诱发炎性细胞因子的释放,进而干扰细胞线粒体功能,加速椎间盘损伤及退变,是压力等外界因子导致椎间盘退变的重要炎性细胞递质。目的：分析一氧化氮及一氧化氮合酶抑制剂烟酰胺对兔髓核细胞线粒体功能的影响及其与髓核细胞生物学行为的相关性。方法：将体外培养的兔腰椎间盘髓核细胞分为6组,正常空白对照组、10μmol/L硝普钠组、100μmol/L硝普钠组、200μmol/L硝普钠组、0.05 g/L烟酰胺组（100μmol/L硝普钠＋0.05 g/L烟酰胺）、0.5 g/L烟酰胺组（加入100μmol/L硝普钠和0.5 g/L烟酰胺干预）,向各组培养基内加入不同剂量的一氧化氮供体硝普钠及烟酰胺进行干预。干预3 d后检测髓核细胞增殖活力、细胞内ATP浓度、细胞内活性氧水平、细胞内一氧化氮合酶活性以及髓核细胞线粒体膜电位。结果与结论：①兔髓核细胞经不同浓度的硝普钠干预3 d后,细胞内一氧化氮合酶量随硝普钠浓度加大而增加、ATP浓度则随着减小,与正常对照组比较差异有显著性意义（P〈0.01）;②硝普钠组可提高髓核细胞内活性氧水平,烟酰胺组呈剂量依赖性改善因硝普钠干预下的细胞内活性氧水平（P〈0.01）;③硝普钠组可引起髓核细胞膜电位下降,烟酰胺组可减轻因硝普钠引起的膜电位下降（P〈0.01）;④与硝普钠组比较烟酰胺组也呈剂量依赖性促进髓核细胞增殖（P〈0.01）及改善髓核细胞的增殖活力,2组之间差异有显著性意义（P〈0.01）;⑤结果说明,过量一氧化氮可损伤兔髓核细胞线粒体功能而导致细胞能量代谢障碍,烟酰胺能够通过抑制一氧化氮的合成以及保护椎间盘细胞线粒体功能和改善细胞能量代谢,有助于预防椎间盘退变。

英文摘要：

BACKGROUND：Nitric oxide can interfere with the function of mitochondria, and accelerate the intervertebral disc damage and degeneration by interfering with the release of inflammatory cytokines. Nitric oxide is an important inflammatory cel medium leading to degeneration of intervertebral disc induced by pressure and other external factors. OBJECTIVE：To investigate the regulatory effect of nitric oxide and nitric oxide synthase inhibitor niacinamide on mitochondrial function and its association with biological behavior of rabbit nucleus pulposus. METHODS：Cultured nucleus pulposus cel s of rabbit lumbar intervertebral disc were randomly divided into six groups：normal blank control group, 10μmol/L sodium nitroprusside group, 100μmol/L sodium nitroprusside group, 200μmol/L sodium nitroprusside group, 0.05 g/L nicotinamide group （100μmol/L sodium nitroprusside＋0.05g/L nicotinamide）, and 0.5 g/L nicotinamide group （100μmol/L sodium nitroprusside and 0.5 g/L nicotinamide）. Different doses of nitric oxide donor sodium nitroprusside and nicotinamide were added in the medium of each group. Three days after intervention, cel proliferation activity, intracel ular ATP concentration, cel nitric oxide synthase activity, cel ular reactive oxygen species level, and mitochondrial membrane potential were detected respectively. RESULTS AND CONCLUSION：（1） After 3 days of rabbit nucleus pulposus cel s intervened by different concentrations of sodium nitroprusside, intracel ular nitric oxide synthase content increased with sodium nitroprusside volume increase, and ATP concentration decreased along with sodium nitroprusside volume increase;there were significantly differences between the normal control group and sodium nitroprusside groups （P〈0.01）. （2） Reactive oxygen species could be increased in the sodium nitroprusside group. Niacinamide groups indicated a dose-dependent manner to improve the increase of cel ular reactive oxygen species levels with sodium nitroprusside intervention （P〈0