Waring W S, Convery A, Mishra V, Shenkin A, Webb D J, Maxwell S R J
Clinical Pharmacology Unit and Research Centre, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, Scotland, UK.
Clin Sci (Lond). 2003 Oct;105(4):425-30. doi: 10.1042/CS20030149.
Uric acid (UA) possesses free-radical-scavenging properties, and systemic administration is known to increase serum antioxidant capacity. However, it is not known whether this protects against oxidative stress. The effects of raising UA concentration were studied during acute aerobic physical exercise in healthy subjects, as a model of oxidative stress characterized by increased circulating 8-iso-prostaglandin F2alpha (8-iso-PGF2alpha) concentrations. Twenty healthy subjects were recruited to a randomized double-blind placebo-controlled crossover study, and underwent systemic administration of 0.5 g of UA in 250 ml of 0.1% lithium carbonate/4% dextrose vehicle or vehicle alone as control. Subjects performed high-intensity aerobic exercise for 20 min to induce oxidative stress. Plasma 8-iso-PGF2alpha concentrations were determined at baseline, after exercise and after recovery for 20 min. A single bout of high-intensity exercise caused a significant increase in plasma 8-iso-PGF2alpha concentrations from 35.0 +/- 4.7 pg/ml to 45.6 +/- 6.7 pg/ml (P<0.01). UA administration raised serum urate concentration from 293 +/- 16 to 487 +/- 16 micromol/l (P<0.001), accompanied by increased serum antioxidant capacity from 1786+/-39 to 1899 +/- 45 micromol/l (P<0.01). UA administration abolished the exercise-induced elevation of plasma 8-iso-PGF2alpha concentrations. High UA concentrations are associated with increased serum antioxidant capacity and reduced oxidative stress during acute physical exercise in healthy subjects. These findings indicate that the antioxidant properties of UA are of biological importance in vivo.
尿酸（UA）具有清除自由基的特性，已知全身给药可提高血清抗氧化能力。然而，目前尚不清楚这是否能预防氧化应激。在健康受试者进行急性有氧运动期间，研究了提高UA浓度的效果，该运动作为以循环中8-异前列腺素F2α（8-异-PGF2α）浓度升高为特征的氧化应激模型。招募了20名健康受试者参加一项随机双盲安慰剂对照交叉研究，受试者接受以250 ml 0.1%碳酸锂/4%葡萄糖溶液全身给药0.5 g UA，或仅给予溶液作为对照。受试者进行20分钟的高强度有氧运动以诱导氧化应激。在基线、运动后和恢复20分钟后测定血浆8-异-PGF2α浓度。单次高强度运动导致血浆8-异-PGF2α浓度从35.0±4.7 pg/ml显著增加至45.6±6.7 pg/ml（P<0.01）。给予UA使血清尿酸盐浓度从293±16升高至487±16 μmol/l（P<0.001），同时血清抗氧化能力从1786±39升高至1899±45 μmol/l（P<0.01）。给予UA消除了运动诱导的血浆8-异-PGF2α浓度升高。在健康受试者急性体育锻炼期间，高UA浓度与血清抗氧化能力增加和氧化应激降低相关。这些发现表明UA的抗氧化特性在体内具有生物学重要性。
