Mazeaud F, Michelson A M
Ann Nutr Aliment. 1980;34(2):351-63.
In this comprehensive approach, inhibition of autoxidation of PUFA by SOD or other enzymes has been studied. The systems used were: 1) in miscible media in which enzyme, substrat, and peroxidation products are soluble; 2) in non-miscible media such as emulsions; 3) in heterogenous media containing subcellular fragments or whole blended tissue. Depending on experimental conditions, inhibition or activation of peroxidation by SOD can be observed in miscible systems. Other enzymes such as phospholipase A, xanthine oxidase, or horseradish peroxidase are protective in heterogeneous media. Moreover, PUFA hydroperoxide are scavenged by glutathione peroxidase which thus could lessen the autocatalytic effects encountered during peroxidation. Enzymatic inhibition of autoxidation in emulsions was not observed. We conclude that superoxide ion does not play a major role in the initiation of peroxidation and that it may very well act as a free radical chain terminator. In addition, other enzymes such as xanthine oxidase, horseradish peroxidase or phospholipase A show an effective although empirical protection against autoxidation in homogenates of tissues.
在这种综合方法中，已经研究了超氧化物歧化酶（SOD）或其他酶对多不饱和脂肪酸（PUFA）自氧化的抑制作用。所使用的体系包括：1）在酶、底物和过氧化产物均可溶解的互溶介质中；2）在不互溶介质如乳液中；3）在含有亚细胞碎片或整个匀浆组织的非均相介质中。根据实验条件，在互溶体系中可以观察到SOD对过氧化的抑制或激活作用。其他酶如磷脂酶A、黄嘌呤氧化酶或辣根过氧化物酶在非均相介质中具有保护作用。此外，谷胱甘肽过氧化物酶可以清除PUFA氢过氧化物，从而减轻过氧化过程中遇到的自催化作用。在乳液中未观察到酶对自氧化的抑制作用。我们得出结论，超氧离子在过氧化引发过程中不起主要作用，它很可能作为自由基链终止剂发挥作用。此外，其他酶如黄嘌呤氧化酶、辣根过氧化物酶或磷脂酶A在组织匀浆中对自氧化表现出有效的（尽管是经验性的）保护作用。
