Human Granulocyte Generation of Hydroxyl
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چکیده
As human leukocytes phagocytize, there is an associated burst of oxygen consumption (1), emission of light (chemiluminescence) (2), stimulation of the hexose monophosphate shunt (1), and the production of a variety of oxygen related toxic agents (3). These events appear to comprise an integral part of the anti-bacterial mechanism (4). Hypothesized mediators of the oxygen-dependent bactericidal event include superoxide anion (02-), hydrogen peroxide (H202), the hydroxyl radical (OH'), and singlet oxygen (021) (reviewed in reference 3). Recent observations have implicated an important role for the OH', a potent oxidant, in both the bactericidal mechanism (5) and inflammation (6). In this report, we describe an assay system which provides evidence for the generation of OH' by human granulocytes. The assay system is based on the observation of Beauchamp and Fridovich (7) that the enzyme system xanthine-xanthine oxidase was capable of oxidizing methional (B-methylthiopropionaldehyde) with the generation of ethylene gas (C2H4) as an end product of this reaction. Ethylene generation was inhibited by OH" scavengers and dependent on 02'and H202. They suggested that 02'and H202 interacted via the Haber-Weiss reaction to generate the OH" with subsequent oxidation of methional. We have employed the modification of Heikkila et al. (8) substituting 2-keto-4-thiomethylbutyric acid (KMB) 1 for methional for the detection of OH' as outlined below.
منابع مشابه
Human granulocyte generation of hydroxyl radical
Human granulocytes were capable of oxidizing 2-keto-4 thiomethylbutyric acid to ethylene during phagocytosis or membrane perturbation. The reaction required hydrogen peroxide and superoxide and in addition was inhibited by various hydroxyl radical (OH) scavengers. These observations represent direct evidence for the generation of OH by human granulocytes. Further, inhibition of ethylene generat...
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تاریخ انتشار 1978