长期血液透析患者红细胞膜F_2-isoprostanes及细胞膜流动性的研究（英文）

Erythrocyte Membrane F_2-isoprostanes Relate to Membrane Fluidity in Patients on Long-term Hemodialysis

【目的】探讨建立血浆和红细胞膜的iPF2α-Ⅲ评估血液透析(HD)患者氧化应激状态,并研究细胞膜流动性与氧化应激的关系。【方法】对49名长期血液透析患者和31例健康人检测其血浆和红细胞细胞膜F2-isoprostanes(一个特定的同分异构体iPF2α-Ⅲ)作为体内氧化应激评价的指标,同时利用DPH和TMA DPH评估细胞膜流动性作为一种间接的细胞功能标志。【结果】血液透析患者和正常对照组相比,氧化应激增高,血浆iPF2α-Ⅲ(0.450±0.173与0.236±0.107 nmol/L、P<0.01)和红细胞膜iPF2α-Ⅲ(32.5±7.9与25.7±8.7 pmol/g,P<0.01)。与正常对照组比较血液透析病人红细胞膜流动性降低,DPH(0.230 2±0.004 0与0.224 6±0.004 6,P<0.01)和TMA DPH(0.271 0±0.004 5与0.264 7±0.007 1,P<0.01),血浆的iPF2α-Ⅲ及红细胞膜流动性无相关;血液透析患者红细胞膜的iPF2α-Ⅲ与核心区域细胞膜流动性呈负相关(r=0.630,P<0.01)。在血液透析病人与健康对照组相比较中发现,血液透析病人中的不同时段的红细胞膜上的iPF2α-Ⅲ的含量较健康对照组增高,相对应红细胞的流动性减低。线性回归分析显示血液透析病人不同时段的红细胞膜DPH流动性与红细胞的膜iPF2α-Ⅲ含量相关(幼红细胞r=0.491,P=0.015;成熟红细胞r=0.563,P=0.004;衰老红细胞r=0.460,P=0.024)。【结论】血液透析患者由于长期处于氧化应激增高的状态,此状态造成不同时段的红细胞膜的表面及核心区域的均受到损害。通过检测红细胞膜的iPF2α-III可以评估体内红细胞氧化应激状态的指标。

[Objective] To determine whether plasma and erythrocyte membrane iPF2α-Ⅲ can be established as a marker for assess the increased oxidative stress in hemodialysis （HD） patients and to verify the potential relationships with membrane fluidity related to oxidative stress in HD patients.[Methods] Forty nine patients on long-term hemodialysis and 31 healthy subjects were recruited.Plasma and erythrocyte membrane F2-isoprostanes （one specific isomer iPF2α-Ⅲ） was investigated as a marker for in vivo oxidative stress assessment.Membrane fluidity in both core with 1,6-diphenylhexatriene （DPH） and surface regions with trimethylammonium-DPH （TMA-DPH） were assessed and used as an indirect marker of cellular function.[Results] Both plasma iPF2α-Ⅲ （0.450 ± 0.173 vs.0.236 ± 0.107 nmol/L,P＜ 0.01） and membrane iPF2α-Ⅲ （32.5 ± 7.9 vs.25.7 ± 8.7 pmol/g protein,P ＜0.01）showed that hemodialysis patients had increased oxidative stress than control subjects.Erythrocyte membrane fluidity was decreased in HD patients compared with normal controls measured by DPH （0.2302 ± 0.0040 vs 0.2246 ± 0.0046,P＜0.01） and TMA-DPH （0.2710 ± 0.0045 vs 0.2647 ± 0.0071,P ＜ 0.01） anisotropy.There was no correlation between plasma total iPF2α-Ⅲ and membrane fluidity;and erythrocyte membrane iPF2α-Ⅲ was inversely correlated with the core region membrane fluidity in HD patients （r =0.630,P ＜ 0.00）.Furthermore,membrane iPF2α-Ⅲ content and membrane anisotropy values from different fractions according to their ages as old,middle and young erythrocytes in HD patients were significantly higher than those in the corresponding fractions of healthy controls.Comparing with erythrocytes in the young fraction,membrane iPF2α-Ⅲ,DPH anisotropy and TMA-DPH anisotropy in the older cells were all significantly higher.Linear regression analysis,the effects of membrane iPF2α-Ⅲ on DPH anisotropy in different aged cells were similar for the HD patients （Young r =0.491,P =0.015;Middle age r =0.563,P =0.004;Old r =0.460,P =0.024）.[Conclusions] HD patients were under increased oxidative stress and oxidative damages on both core and surface regions of erythrocyte membranes,and all circulating erythrocytes of different ages were affected.Membrane iPF2α-Ⅲ content can be considered as a tissue marker for in vivo erythrocyte oxidative stress assessment.