Glantzounis Georgios K, Rocks Sophie A, Sheth Hemant, Knight Iona, Salacinski Henryk J, Davidson Brian R, Winyard Paul G, Seifalian Alexander M
Hepatic Hemodynamic Unit, Academic Division of Surgical and Interventional Sciences, University College London, Rowland Hill Street, London NW3 2QG, UK.
Free Radic Biol Med. 2007 Mar 15;42(6):882-92. doi: 10.1016/j.freeradbiomed.2006.12.020. Epub 2006 Dec 22.
Plasma S-nitrosothiols (RSNOs) may act as a circulating form of nitric oxide that affects vascular function and platelet aggregation. Their role in liver ischemia/reperfusion (I/R) injury is largely unknown. The aim of the present study was to investigate the changes in plasma RSNOs following liver I/R injury. Two groups of New Zealand white rabbits were used (n=6, each): the I/R group underwent 60 min lobar liver ischemia and 7 h reperfusion, while the sham group underwent laparotomy but no liver ischemia. Serial RSNO levels were measured in plasma by electron paramagnetic resonance (EPR) spectrometry, nitrite/nitrates by capillary electrophoresis, hepatic microcirculation by laser Doppler flowmetry, redox state of hepatic cytochrome oxidase by near-infrared spectroscopy, liver iNOS mRNA expression by reverse transcription-polymerase chain reaction (RT-PCR) and the oxidation of dihydrorhodamine to rhodamine by fluorescence. The effect of the antioxidant N-acetylcysteine (NAC) on RSNOs formation and DHR oxidation was tested in a third group of animals (n=6) undergoing lobar liver I/R. Hepatic I/R was associated with a significant increase in plasma RSNOs, plasma nitrites, hepatic iNOS mRNA expression, impairment in hepatic microcirculation, decrease in the redox state of cytochrome oxidase, and significant production of rhodamine. The changes were more obvious during the late phase of reperfusion (>4 h). NAC administration decreased plasma RSNOs and oxidation of DHR to RH (P<0.05, 5 and 7 h postreperfusion, respectively). These results suggest that significant upregulation of nitric oxide synthesis during the late phase of reperfusion is associated with impairment in microcirculation and mitochondrial dysfunction. Plasma S-nitrosothiols are a good marker of this nitric oxide-mediated hepatotoxicity.
血浆 S-亚硝基硫醇（RSNOs）可能作为一氧化氮的循环形式，影响血管功能和血小板聚集。它们在肝脏缺血/再灌注（I/R）损伤中的作用尚不清楚。本研究旨在探讨肝脏 I/R 损伤后血浆 RSNOs 的变化。使用两组新西兰白兔（每组 n = 6）：I/R 组经历 60 分钟的叶状肝缺血和 7 小时再灌注，而假手术组进行剖腹手术但无肝缺血。通过电子顺磁共振（EPR）光谱法测量血浆中 RSNO 的系列水平，通过毛细管电泳测量亚硝酸盐/硝酸盐，通过激光多普勒血流仪测量肝微循环，通过近红外光谱测量肝细胞色素氧化酶的氧化还原状态，通过逆转录-聚合酶链反应（RT-PCR）测量肝诱导型一氧化氮合酶（iNOS）mRNA 表达，并通过荧光测量二氢罗丹明氧化为罗丹明。在第三组经历叶状肝 I/R 的动物（n = 6）中测试抗氧化剂 N-乙酰半胱氨酸（NAC）对 RSNOs 形成和二氢罗丹明（DHR）氧化的影响。肝 I/R 与血浆 RSNOs、血浆亚硝酸盐、肝 iNOS mRNA 表达显著增加、肝微循环受损、细胞色素氧化酶氧化还原状态降低以及罗丹明的大量产生有关。这些变化在再灌注后期（>4 小时）更为明显。给予 NAC 可降低血浆 RSNOs 和 DHR 氧化为罗丹明（分别在再灌注后 5 小时和 7 小时，P<0.05）。这些结果表明，再灌注后期一氧化氮合成的显著上调与微循环损伤和线粒体功能障碍有关。血浆 S-亚硝基硫醇是这种一氧化氮介导的肝毒性的良好标志物。
