Zima T, Janebová M, Nemecek K, Bártová V
Institute of Medical Chemistry and Biochemistry, First Faculty of Medicine Charles University, Prague, Czech Republic.
Ren Fail. 1998 May;20(3):505-12. doi: 10.3109/08860229809045139.
The biological effects of reactive oxygen species and other radicals controlled by antioxidant mechanisms are modified by various enzymes and other substrates. Antioxidant substrates are divided into those with lipophilic and hydrophilic groups. Retinol and tocopherol are the main representations of lipophilic antioxidants. The aim of the present study was to describe the changes of retinol and alpha-tocopherol which occurred in hemodialysis (HD) patients in respect to the influence of antioxidant systems. The experimental group consisted of 14 patients on regular HD treatment. The control group consisted of 14 healthy blood donors. HPLC was used to measure retinol and alpha-tocopherol in serum. We found that the retinol concentration was significantly higher in HD patients compared to controls (2.35 +/- 0.95 versus 0.90 +/- 0.23 mg/L, p < 0.0001). The concentration of alpha-tocopherol in serum was not different in both study groups (7.32 +/- 3.01 versus. 8.94 +/- 3.57 mg/L). A review of the MEDLINE database since 1985 found a few references concerning these important antioxidant vitamins in HD patients and these contained contrasting results. It has been suggested that some of the complications related to HD including cardiovascular complications, anemia and atherosclerosis may be due to ineffective antioxidant systems and/or to increased free oxygen radical production. The question about supplementation of antioxidants in HD patients is open although there are some positive data regarding the use of moderate and safe selenium supplementation in HD patients. HD patients treated by erythropoietin had increased plasma concentration of retinol and normal level of alpha-tocopherol compared to healthy group. However, this positive finding did not affect lipid peroxidation, which is increased in HD patients and leads to some complications during HD treatment.
由抗氧化机制控制的活性氧和其他自由基的生物效应会被各种酶和其他底物所改变。抗氧化底物分为具有亲脂性和亲水性基团的两类。视黄醇和生育酚是亲脂性抗氧化剂的主要代表。本研究的目的是描述血液透析（HD）患者体内视黄醇和α-生育酚的变化及其对抗氧化系统的影响。实验组由14名接受常规血液透析治疗的患者组成。对照组由14名健康献血者组成。采用高效液相色谱法测定血清中的视黄醇和α-生育酚。我们发现，HD患者的视黄醇浓度显著高于对照组（2.35±0.95 vs 0.90±0.23 mg/L，p<0.0001）。两组研究对象血清中α-生育酚的浓度没有差异（7.32±3.01 vs 8.94±3.57 mg/L）。对1985年以来的MEDLINE数据库进行检索后发现，关于HD患者体内这些重要抗氧化维生素的参考文献较少，且结果相互矛盾。有人提出，一些与HD相关的并发症，包括心血管并发症、贫血和动脉粥样硬化，可能是由于抗氧化系统无效和/或自由基产生增加所致。尽管有一些关于HD患者适度和安全补充硒的积极数据，但HD患者是否补充抗氧化剂的问题仍未解决。与健康组相比，接受促红细胞生成素治疗的HD患者血浆视黄醇浓度升高，α-生育酚水平正常。然而，这一积极发现并未影响脂质过氧化，HD患者的脂质过氧化增加，并导致HD治疗期间出现一些并发症。
