Di Giuseppe Danila, Frosali Simona, Priora Raffaella, Di Simplicio Francesca Cherubini, Buonocore Giuseppe, Cellesi Carla, Capecchi Pier Leopoldo, Pasini Franco Laghi, Lazzerini Pietro Enea, Jakubowski Hieronim, Di Simplicio Paolo
Department of Neuroscience, Pharmacology Unit, University of Sienna, Sienna, Italy.
J Lab Clin Med. 2004 Nov;144(5):235-45. doi: 10.1016/j.lab.2004.06.006.
We assayed the redox forms of cysteine (reduced [CSH], oxidized [CSSC], and bound to protein [CS-SP]), cysteinylglycine (CGSH; cysteinylgycine disulfide [CGSSGC] and cysteinylglycine-protein mixed disulfide [CGS-SP]), glutathione (GSH; glutathione disulfide [GSSG] and glutathione-protein mixed disulfide [GS-SP]), homocysteine (Hcy; homocystine [HcyS] and homocystine-protein mixed disulfides [bHcy]), and protein sulfhydryls in the plasma of healthy subjects (divided into 8 groups ranging in age from birth to 70 years) and patients with mild hyperhomocysteinemia associated with cardiovascular disease (heart-transplant patients) or vascular atherosclerosis, with or without renal failure. In healthy individuals, levels of disulfides and protein-mixed disulfides were more abundant than those of thiols, and those of protein-thiol mixed disulfides were higher than disulfides. Concentrations of CSH, GSH, and CGSH in the various groups had profiles characterized by a maximum over time. The concentration of Hcy was unchanged up to the age of 30 years, after which it increased. CSSC concentration increased gradually with age, whereas concentrations of the other disulfides were essentially unchanged. By contrast, the concentrations of all protein-thiol mixed disulfides, especially those with CSH, increased gradually with age. Ranks of distribution of the reduced forms changed with age (at birth, CSH > CGSH > GSH > Hcy; in 1- to 2-year-olds, CSH > GSH > CGSH > Hcy; and in 51- to 70-year-olds, CSH > CGSH = GSH > Hcy), whereas those of disulfides and protein-thiol mixed disulfides were substantially unchanged (in all age groups, CSSC > CGSSGC > GSSG = HcyS and CS-SP > CGS-SP > bHcy > GS-SP). In patients with pathologic conditions, plasma levels of disulfide forms CSSC, HcyS, CS-SP, and bHcy were significantly increased, whereas other redox forms of thiols were unchanged or showed variations opposite (increasing or decreasing) to control values. Maximal increases in disulfides and protein-thiol mixed disulfides were associated with renal failure. Our data suggest that increases in plasma bHcy concentrations in subjects with pathologic conditions were more likely the result of activation of thiol-disulfide exchange reactions between free reduced Hcy and CS-SP than of a direct action of reactive oxygen species.
我们检测了健康受试者（分为8组，年龄从出生到70岁）以及患有与心血管疾病相关的轻度高同型半胱氨酸血症（心脏移植患者）或血管动脉粥样硬化（伴或不伴肾衰竭）的患者血浆中半胱氨酸的氧化还原形式（还原型[CSH]、氧化型[CSSC]以及与蛋白质结合型[CS-SP]）、半胱氨酰甘氨酸（CGSH；半胱氨酰甘氨酸二硫化物[CGSSGC]和半胱氨酰甘氨酸 - 蛋白质混合二硫化物[CGS-SP]）、谷胱甘肽（GSH；谷胱甘肽二硫化物[GSSG]和谷胱甘肽 - 蛋白质混合二硫化物[GS-SP]）、同型半胱氨酸（Hcy；同型胱氨酸[HcyS]和同型胱氨酸 - 蛋白质混合二硫化物[bHcy]）以及蛋白质巯基。在健康个体中，二硫化物和蛋白质混合二硫化物的水平比硫醇更丰富，且蛋白质 - 硫醇混合二硫化物的水平高于二硫化物。各年龄组中CSH、GSH和CGSH的浓度随时间呈现出一个最大值的变化趋势。Hcy浓度在30岁之前保持不变，之后升高。CSSC浓度随年龄逐渐增加，而其他二硫化物的浓度基本不变。相比之下，所有蛋白质 - 硫醇混合二硫化物的浓度，尤其是与CSH相关的，随年龄逐渐增加。还原形式的分布顺序随年龄变化（出生时，CSH > CGSH > GSH > Hcy；1至2岁时，CSH > GSH > CGSH > Hcy；51至70岁时，CSH > CGSH = GSH > Hcy），而二硫化物和蛋白质 - 硫醇混合二硫化物的分布顺序基本不变（在所有年龄组中，CSSC > CGSSGC > GSSG = HcyS且CS-SP > CGS-SP > bHcy > GS-SP）。在患有病理状况的患者中，二硫化物形式CSSC、HcyS、CS-SP和bHcy的血浆水平显著升高，而硫醇的其他氧化还原形式不变或呈现与对照值相反（升高或降低）的变化。二硫化物和蛋白质 - 硫醇混合二硫化物的最大增加与肾衰竭相关。我们的数据表明，患有病理状况的受试者血浆中bHcy浓度的升高更可能是游离还原型Hcy与CS-SP之间硫醇 - 二硫化物交换反应激活的结果，而非活性氧的直接作用。
