Bellavite P, Serra M C, Davoli A, Rossi F
Inflammation. 1982 Mar;6(1):21-9. doi: 10.1007/BF00910716.
Recent studies have demonstrated that the activated NADPH oxidase, the enzyme responsible for the stimulation of O2 consumption with O2 formation during phagocytosis, is located in the plasma membrane of leukocytes. The present work deals with whether the activation induced by phagocytosis involves the enzyme of the entire membrane or only that of the portion of the membrane that interacts with the phagocytosable particle and forms the phagosome. The results presented show that the activity of the NADPH oxidase of phagosomal membrane, isolated by centrifugation of homogenates on discontinuous sucrose gradients, is increased 12.6-fold with respect that of homogenate. In contrast, the activities of 5'-nucleotidase and of acid p-nitrophenyl phosphatase, enzyme markers of the plasma membrane not activated during phagocytosis and uniformly distributed on the entire membrane, are increased only about three-fold with respect to that of homogenate. These results indicate that during phagocytosis and activation of NADPH oxidase is a segmentary response that involves only the enzyme that forms the phagocytic vacuole. This fact is relevant for the function of toxic intermediates of oxygen reduction that are discharged in direct contact with the engulfed agent.
最近的研究表明，活化的NADPH氧化酶，即负责在吞噬作用期间刺激氧气消耗并形成超氧阴离子的酶，位于白细胞的质膜中。目前的工作探讨了吞噬作用诱导的活化是涉及整个膜的酶，还是仅涉及与可吞噬颗粒相互作用并形成吞噬体的那部分膜的酶。所呈现的结果表明，通过在不连续蔗糖梯度上对匀浆进行离心分离得到的吞噬体膜的NADPH氧化酶活性，相对于匀浆增加了12.6倍。相比之下，5'-核苷酸酶和酸性对硝基苯磷酸酶的活性，这些是在吞噬作用期间未活化且均匀分布在整个膜上的质膜酶标记物，相对于匀浆仅增加了约三倍。这些结果表明，在吞噬作用期间NADPH氧化酶的活化是一种局部反应，仅涉及形成吞噬泡的酶。这一事实与直接与被吞噬物质接触释放的氧还原毒性中间体的功能相关。
