Liu J, Yeo H C, Doniger S J, Ames B N
Division of Biochemistry and Molecular Biology, University of California, Berkeley 94720, USA.
Anal Biochem. 1997 Feb 15;245(2):161-6. doi: 10.1006/abio.1996.9990.
The oxidation of lipids, lipid peroxidation, is usually assayed with thiobarbituric acid (TBA). We compare the TBA assay measuring TBA-reactive substances (TBARS), and a new gas chromatography-mass spectrometric (GC-MS) assay measuring malondialdehyde (MDA) with unsaturated fatty acids and biological samples. The extent of oxidation to different unsaturated fatty acids is related to the total number of bis-allylic positions, the position of the first double bond from the methyl terminus, and the lipid chain length. The extent of oxidation of different biological samples or organs is related to the component polyunsaturated fatty acids. Both the GC-MS and TBA assays give parallel results for oxidation of unsaturated fatty acids and biological samples. The GC-MS assay is about two- to sixfold more sensitive than the TBA assay for oxidation of unsaturated fatty acids. In contrast, the TBA assay gives about two- to sixfold higher TBARS than MDA by GC-MS assay in biological samples, possibly due to the nonspecificity and artifactual formation of derivatives in the acid-heating step of the TBA assay. The GC-MS assay is shown to be useful in oxidation-related cell culture studies with as few as 250,000 neural cells. These results suggest that the GC-MS assay is a useful, sensitive, and specific assay for lipid peroxidation. The TBA assay is also quite useful because of its sensitivity and simplicity, if one clearly understands its nonspecificity.
脂质的氧化，即脂质过氧化作用，通常用硫代巴比妥酸（TBA）进行测定。我们比较了测量TBA反应性物质（TBARS）的TBA测定法，以及一种新的气相色谱 - 质谱联用（GC-MS）测定法，该方法用于测量与不饱和脂肪酸和生物样品相关的丙二醛（MDA）。不同不饱和脂肪酸的氧化程度与双烯丙基位置的总数、从甲基末端起第一个双键的位置以及脂质链长度有关。不同生物样品或器官的氧化程度与其中的多不饱和脂肪酸成分有关。GC-MS测定法和TBA测定法对于不饱和脂肪酸和生物样品的氧化给出了平行的结果。对于不饱和脂肪酸的氧化，GC-MS测定法的灵敏度比TBA测定法高约两到六倍。相比之下，在生物样品中，TBA测定法所测得的TBARS比GC-MS测定法测得的MDA高约两到六倍，这可能是由于TBA测定法在酸加热步骤中存在非特异性和衍生物的人为形成。结果表明，GC-MS测定法在涉及少至250,000个神经细胞的氧化相关细胞培养研究中很有用。这些结果表明，GC-MS测定法是一种用于脂质过氧化作用的有用、灵敏且特异的测定法。如果清楚了解其非特异性，TBA测定法因其灵敏度和简便性也相当有用。
