生物样本中过氧化脂质定量测定的三种方法比较

目的　探讨在生物样本体系中测定过氧化脂质 (L PO)的较理想方法。方法　用目前最常用的 FOX法 ,改进碘量法 ,TBARS法同时测定不同生物样本体系中的 L PO浓度 ,并以线型性 ,准确度 ,精确度 ,稳定性和检测效率等指标评估、比较此三种方法的优劣。样本体系包括萃取的低密度脂蛋白 (L DL) ,细胞培养上清液 ,人血浆。结果　在萃取的 L DL样本体系中 ,FOX法显示出对 L PO最敏感的检测效率 ,并具有良好的准确性和精确度。但在细胞培养上清液和人血浆中 ,改进碘量法和 TBARS法的质量评估指标则优于 FOX法。在准确度评估实验中 ,FOX法对人血浆中的加样回收率明显偏低 (6 1.92 %± 2 .92 % ,碘量法 99.0 0 %± 2 .6 5 % ,TBARS法 10 1.6 3%±12 .0 0 % ) ,重复性也差 (评估精确度的变异系数 CV:FOX法为 19.15 % ,碘量法 4 .36 % ,TBARS法 3.14 % )。在线型性评估和稳定性评估实验中 ,三种方法皆显示出良好的性能。在人血浆中 L PO浓度的测值 ,改进碘量法为(14 .189± 4 .889)μm ol/ L ,TBARS法为 (0 .936± 0 .4 6 2 )μmol/ L ,上述测值与其它作者的报道相近。结论　在相对纯净的样本体系中 ,FOX法显示出对 L PO最敏感的检测效能。但在复杂样本体系中 ,改进碘量法和 TBARS法测定 L PO的各项质量指标则优于 FOX

Comparison of Three Methods for Quantitative Analysis of LPO in Different Biological Samples

OBJECTIVE: To explore the optimized methods for detecting lipid peroxide (LPO) in biological samples and the reference value of LPO in human plasma. METHODS: Three most commonly adopted methods were used for detecting LPO in different biological samples simultaneously, and then their linearity, accuracy, precision, stability and detecting efficiency were compared. The methods were FOX assay, Modified iodometric assay and TBARS assay. The standard curve (linearity evaluation), rate of sample recovery (accuracy evaluation), reproducibility (precision evaluation), stability of reading number (stability evaluation), as well as the detected values of LPO in different sample systems by three methods simultaneously (detecting efficiency) were evaluated. The sample systems were: isolated low-density lipoprotein (LDL), supernatant of cell culture, and human plasma. RESULTS: When applied to detecting LPO in the isolated LDL sample system, FOX assay was found to have the most sensitive detecting efficiency, good accuracy and precision. When applied to detecting LPO in the supernatant of cell culture and human plasma sample systems, the Modified iodometric assay and TBARS assay showed better function than FOX assay; the rate of sample recovery of FOX assay 61.92% +/- 2.92% was obviously lower as compared with 99.00% +/- 2.65% of modified iodometric assay and 101.63% +/- 12.00% of TBARS assay; and the reproducibility of FOX assay 19.15% was also lower as compared with 4.36% of Modified iodometric assay and 3.14% of TBARS assay. The three methods all showed fine linearity and stability. The values of LPO concentration in normal human plasma were (14.189 +/- 4.889) mumol/L by Modified iodometric assay and (0.936 +/- 0.462) mumol/L by TBARS assay; these values were close to those in other reports. CONCLUSION: FOX assay was found to be most sensitive in the three methods for measurement of LPO in a relative pure sample system (such as isolated LDL). In complex sample system, however, the Modified iodometric assay and TBARS assay showed better function. The authors suggest that suitable method be chosen according to the nature of sample, that more than one method be chosen for plasma LPO assay in the same planned analysis, and that Modified iodometric assay and TBARS assay be worth the first choice.