Oxidative stress in patients with phenylketonuria.
Oxidative stress in patients with phenylketonuria.
复制标题
苯丙酮尿症患者的氧化应激。
DOI：
10.1016/j.bbadis.2005.02.005
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
C. Vargas
中科院分区：
文献类型：
--
作者：
L. Sirtori;C. Dutra;D. Fitarelli;A. Sitta;A. Haeser;A. Barschak;M. Wajner;D. Coelho;S. Llesuy;A. Belló;R. Giugliani;M. Deon;C. Vargas
苯丙酮尿症（PKU）是由苯丙氨酸-4-羟化酶缺乏引起的常染色体隐性遗传病，苯丙氨酸-4-羟化酶是一种肝脏特异性酶，可催化l-苯丙氨酸（Phe）羟基化为l-酪氨酸（Tyr）。缺乏这种酶会导致Phe在患者的组织和血浆中积累。本病的临床特征是智力低下和其他神经学特征。人们对脑损伤的机制了解甚少。由于有毒代谢物的积累导致过多的自由基产生，在一些先天的中间代谢错误中观察到氧化应激，这可能是限制饮食对抗氧化状态的结果。在本研究中，我们评估了PKU患者血浆中的各种氧化应激参数，即硫代巴比妥酸反应物质（TBA-RS）和总抗氧化反应活性（TAR）。同时测定红细胞中过氧化氢酶（CAT）、超氧化物歧化酶（SOD）和谷胱甘肽过氧化物酶（GSH-Px）的活性。我们观察到，苯酮尿酸患者血浆TBA-RS测量值显著升高，表明脂质过氧化刺激，血浆TAR降低，反映快速处理活性物质增加的能力不足。红细胞GSH-Px活性降低。因此，我们推测氧化应激参与了PKU组织损伤的病理生理过程。
Phenylketonuria (PKU) is an autossomal recessive disease caused by phenylalanine-4-hydroxylase deficiency, which is a liver-specific enzyme that catalyzes the hydroxylation of l-phenylalanine (Phe) to l-tyrosine (Tyr). The deficiency of this enzyme leads to the accumulation of Phe in the tissues and plasma of patients. The clinical characterization of this disease is mental retardation and other neurological features. The mechanisms of brain damage are poorly understood. Oxidative stress is observed in some inborn errors of intermediary metabolism owing to the accumulation of toxic metabolites leading to excessive free radical production and may be a result of restricted diets on the antioxidant status. In the present study we evaluated various oxidative stress parameters, namely thiobarbituric acid-reactive species (TBA-RS) and total antioxidant reactivity (TAR) in the plasma of PKU patients. The activities of the antioxidant enzymes catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were also measured in erythrocytes from these patients. It was observed that phenylketonuric patients present a significant increase of plasma TBA-RS measurement, indicating a stimulation of lipoperoxidation, as well as a decrease of plasma TAR, reflecting a deficient capacity to rapidly handle an increase of reactive species. The results also showed a decrease of erythrocyte GSH-Px activity. Therefore, it is presumed that oxidative stress is involved in the pathophysiology of the tissue damage found in PKU.
高苯丙氨酸血症永久性脑功能障碍的机制。
DOI：
10.1016/0885-4505(91)90078-y
发表时间：
1991
期刊：
Biochemical medicine and metabolic biology
影响因子：
--
作者：
Hommes,FA
通讯作者：
Hommes,FA