Musacco-Sebio Rosario, Saporito-Magriñá Christian, Semprine Jimena, Torti Horacio, Ferrarotti Nidia, Castro-Parodi Mauricio, Damiano Alicia, Boveris Alberto, Repetto Marisa G
Department of General and Inorganic Chemistry, School of Pharmacy and Biochemistry, University of Buenos Aires, C1113AAD Buenos Aires, Argentina.
Department of Physics, School of Pharmacy and Biochemistry, University of Buenos Aires, C1113AAD Buenos Aires, Argentina.
J Inorg Biochem. 2014 Aug;137:94-100. doi: 10.1016/j.jinorgbio.2014.04.014. Epub 2014 Apr 30.
The rat liver antioxidant response to Fe and Cu overloads (0-60mg/kg) was studied. Dose- and time-responses were determined and summarized by t1/2 and C50, the time and the liver metal content for half maximal oxidative responses. Liver GSH (reduced glutathione) and GSSG (glutathione disulfide) were determined. The GSH content and the GSH/GSSG ratio markedly decreased after Fe (58-66%) and Cu (79-81%) loads, with t1/2 of 4.0 and 2.0h. The C50 were in a similar range for all the indicators (110-124μgFe/g and 40-50μgCu/g) and suggest a unique free-radical mediated process. Hydrophilic antioxidants markedly decreased after Fe and Cu (60-75%; t1/2: 4.5 and 4.0h). Lipophilic antioxidants were also decreased (30-92%; t1/2: 7.0 and 5.5h) after Fe and Cu. Superoxide dismutase (SOD) activities (Cu,Zn-SOD and Mn-SOD) and protein expression were adaptively increased after metal overloads (Cu,Zn-SOD: t1/2: 8-8.5h and Mn-SOD: t1/2: 8.5-8.0h). Catalase activity was increased after Fe (65%; t1/2: 8.5h) and decreased after Cu (26%; t1/2: 8.0h), whereas catalase expression was increased after Fe and decreased after Cu overloads. Glutathione peroxidase activity decreased after metal loads by 22-39% with a t1/2 of 4.5h and with unchanged protein expression. GSH is the main and fastest responder antioxidant in Fe and Cu overloads. The results indicate that thiol (SH) content and antioxidant enzyme activities are central to the antioxidant defense in the oxidative stress and damage after Fe and Cu overloads.
研究了大鼠肝脏对铁和铜过载（0 - 60mg/kg）的抗氧化反应。通过t1/2和C50确定并总结剂量和时间反应，t1/2和C50分别为达到半数最大氧化反应的时间和肝脏金属含量。测定了肝脏中的谷胱甘肽（GSH，还原型谷胱甘肽）和氧化型谷胱甘肽（GSSG）。铁（58 - 66%）和铜（79 - 81%）负荷后，GSH含量和GSH/GSSG比值显著降低，t1/2分别为4.0小时和2.0小时。所有指标的C50处于相似范围（110 - 124μg铁/g和40 - 50μg铜/g），提示存在一个独特的自由基介导过程。亲水性抗氧化剂在铁和铜作用后显著降低（60 - 75%；t1/2：4.5小时和4.0小时）。铁和铜作用后，亲脂性抗氧化剂也降低（30 - 92%；t1/2：7.0小时和5.5小时）。金属过载后，超氧化物歧化酶（SOD）活性（铜锌超氧化物歧化酶和锰超氧化物歧化酶）及蛋白表达适应性增加（铜锌超氧化物歧化酶：t1/2：8 - 8.5小时；锰超氧化物歧化酶：t1/2：8.5 - 8.0小时）。铁作用后过氧化氢酶活性增加（65%；t1/2：8.5小时），铜作用后降低（26%；t1/2：8.0小时），而过氧化氢酶表达在铁过载后增加，铜过载后降低。金属负荷后谷胱甘肽过氧化物酶活性降低22 - 39%，t1/2为4.5小时，蛋白表达无变化。在铁和铜过载时，GSH是主要且反应最快的抗氧化剂。结果表明，巯基（SH）含量和抗氧化酶活性在铁和铜过载后的氧化应激及损伤的抗氧化防御中起核心作用。
