Nobili Valerio, Pastore Anna, Gaeta Laura Maria, Tozzi Giulia, Comparcola Daniela, Sartorelli Maria Rita, Marcellini Matilde, Bertini Enrico, Piemonte Fiorella
Division of Hepatology, Children's Hospital and Research Institute "Bambino Gesù," Piazza S. Onofrio, 4, Rome 00165, Italy.
Clin Chim Acta. 2005 May;355(1-2):105-11. doi: 10.1016/j.cccn.2004.12.022.
Oxidative stress and accumulation of excessive fat in the liver may underlie the pathophysiology of nonalcoholic steatohepatitis (NASH). Given that glutathione blood metabolism may represent an indicator of tissue oxidative status, we analysed the blood profile of various forms of glutathione in children with NASH, and we evaluated the presence of systemic oxidative stress by calculating the oxidised/reduced glutathione ratio (GSSG/GSH). Furthermore, we analysed the catalytic activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione transferase (GST), and glutathione reductase (GR) in blood of patients.
Blood samples were obtained from 21 children with NASH and 28 controls. Total, reduced, oxidised, and protein-bound glutathione concentrations were determined by reversed-phase liquid chromatography with fluorescence detection. Antioxidant enzymes were spectrophotometrically assayed by using specific substrates.
Our findings showed a 1.5-fold increase of GSSG in patients, resulting in a significant rise of the GSSG/GSH ratio. SOD, GPx, and GR activities were not significantly different in NASH respect to controls, whereas GST, which provides the second defence line against oxidative stress, was 17.8% increased.
Our data demonstrate an impairment of glutathione metabolism and antioxidant enzyme activities in blood of patients with NASH, supporting a consistent role of free radical cytotoxicity in the pathophysiology of the disease.
氧化应激和肝脏中过多脂肪的积累可能是非酒精性脂肪性肝炎（NASH）病理生理学的基础。鉴于谷胱甘肽血液代谢可能代表组织氧化状态的一个指标，我们分析了NASH患儿各种形式谷胱甘肽的血液特征，并通过计算氧化型/还原型谷胱甘肽比率（GSSG/GSH）评估全身氧化应激的存在情况。此外，我们还分析了患者血液中超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GPx）、谷胱甘肽转移酶（GST）和谷胱甘肽还原酶（GR）的催化活性水平。
采集了21例NASH患儿和28例对照儿童的血样。采用反相液相色谱荧光检测法测定总谷胱甘肽、还原型谷胱甘肽、氧化型谷胱甘肽和蛋白结合型谷胱甘肽的浓度。使用特定底物通过分光光度法测定抗氧化酶活性。
我们的研究结果显示，患者体内GSSG增加了1.5倍，导致GSSG/GSH比率显著升高。NASH患者的SOD、GPx和GR活性与对照组相比无显著差异，而作为抵抗氧化应激第二道防线的GST活性增加了17.8%。
我们的数据表明，NASH患者血液中的谷胱甘肽代谢和抗氧化酶活性受损，这支持了自由基细胞毒性在该疾病病理生理学中发挥的持续作用。
