Cargnoni A, Pasini E, Ceconi C, Ferrari R, Curello S, Benigno M, Visioli O
Cattedra di Cardiologia, Università degli Studi, Brescia.
Cardiologia. 1991 Feb;36(2):123-8.
Peroxidation of membrane phospholipid polyunsaturated fatty acids is considered a major mechanism of the damage occurring during post-ischemic reperfusion. The evidences in support for this mechanism of damage are based on tissue malondialdehyde (MDA) quantitation by the thiobarbituric acid test (TBA-test). In an attempt to verify this topic we have subjected isolated and Langendorff perfused rabbit hearts to a period of 60 min of severe ischemia plus 30 min of reperfusion. At appropriate time points MDA was determined in the tissue by means of TBA-test and directly by reversed phase, high pressure, liquid chromatography (HPLC). We have found no correlation between the 2 compared assays. During reperfusion, there was the formation of non-lipid related, MDA like, TBA-reactive substance which leads to overestimation of the extent of lipid peroxidation. On the contrary, by direct HPLC quantitation, there was a decrease of tissue MDA during ischemia and during the early phases of reperfusion. Our results demonstrate that TBA-test is not a reliable index of lipid peroxidation in organ systems and that MDA accumulation does not precede the evidence of the functional alterations occurring on reperfusion of the previously ischemic myocardium. These results are of relevance in the understanding of the exact mechanism of reperfusion damage as, in the same experimental model, oxy radicals have been shown to be generated and antioxidants are protective.
膜磷脂多不饱和脂肪酸的过氧化被认为是缺血后再灌注期间发生损伤的主要机制。支持这种损伤机制的证据基于通过硫代巴比妥酸试验（TBA试验）对组织丙二醛（MDA）进行定量。为了验证这一主题，我们对离体的、经Langendorff灌注的兔心脏进行了60分钟的严重缺血加30分钟的再灌注。在适当的时间点，通过TBA试验并直接通过反相高压液相色谱法（HPLC）测定组织中的MDA。我们发现这两种比较的检测方法之间没有相关性。在再灌注期间，形成了与脂质无关的、类似MDA的TBA反应性物质，这导致对脂质过氧化程度的高估。相反，通过直接HPLC定量，在缺血期间和再灌注早期组织MDA含量降低。我们的结果表明，TBA试验不是器官系统中脂质过氧化的可靠指标，并且MDA积累并不先于先前缺血心肌再灌注时发生的功能改变的证据。这些结果对于理解再灌注损伤的确切机制具有重要意义，因为在相同的实验模型中，已证明会产生氧自由基且抗氧化剂具有保护作用。
