Shimo Hanae, Nishino Taiko, Tomita Masaru
Institute for Advanced Biosciences, Keio University, 403-1, Daihoji, Tsuruoka, Yamagata 997-0017, Japan.
Adv Hematol. 2011;2011:398945. doi: 10.1155/2011/398945. Epub 2011 Sep 28.
It is well known that G6PD-deficient individuals are highly susceptible to oxidative stress. However, the differences in the degree of metabolic alterations among patients during an oxidative crisis have not been extensively studied. In this study, we applied mathematical modeling to assess the metabolic changes in erythrocytes of various G6PD-deficient patients during hydrogen peroxide- (H(2)O(2)-) induced perturbation and predict the kinetic properties that elicit redox imbalance after exposure to an oxidative agent. Simulation results showed a discrepancy in the ability to restore regular metabolite levels and redox homeostasis among patients. Two trends were observed in the response of redox status (GSH/GSSG) to oxidative stress, a mild decrease associated with slow recovery and a drastic decline associated with rapid recovery. The former was concluded to apply to patients with severe clinical symptoms. Low V(max) and high K(mG6P) of G6PD were shown to be kinetic properties that enhance consequent redox imbalance.
众所周知,葡萄糖-6-磷酸脱氢酶(G6PD)缺乏的个体对氧化应激高度敏感。然而,在氧化危机期间患者之间代谢改变程度的差异尚未得到广泛研究。在本研究中,我们应用数学模型来评估过氧化氢(H₂O₂)诱导的扰动期间各种G6PD缺乏患者红细胞中的代谢变化,并预测暴露于氧化剂后引发氧化还原失衡的动力学特性。模拟结果显示患者之间恢复正常代谢物水平和氧化还原稳态的能力存在差异。在氧化还原状态(谷胱甘肽/氧化型谷胱甘肽,GSH/GSSG)对氧化应激的反应中观察到两种趋势,一种是与缓慢恢复相关的轻度下降,另一种是与快速恢复相关的急剧下降。得出结论,前者适用于具有严重临床症状的患者。G6PD的低最大反应速度(Vmax)和高6-磷酸葡萄糖(G6P)米氏常数(KmG6P)被证明是增强随后氧化还原失衡的动力学特性。