Kimura S, Jellinck P H
Arch Biochem Biophys. 1985 Aug 15;241(1):141-8. doi: 10.1016/0003-9861(85)90370-4.
The high-speed supernatant from homogenates of rat small intestine contains a heat-stable, dialyzable factor which showed a time-dependent inhibition of peroxidase activity in salt extracts of the tissue. The inhibitor was purified by chromatography on Dowex 50W-X8 and identified as xanthine. The inhibition of peroxidase by xanthine was prevented by allopurinol, an inhibitor of xanthine oxidase, and hypoxanthine was also found to be inhibitory. H2O2, produced in the reaction catalyzed by xanthine oxidase, was shown to be directly responsible for the observed inhibition. The time-dependent loss of peroxidase activity in the presence of xanthine or hypoxanthine occurred more rapidly in NH4Cl than in CaCl2 extracts of small intestine and was due to the difference in the initial concentration of H2O2 in these two extracts. The possible relationship between peroxidase and xanthine oxidase in the rat small intestine is discussed.
大鼠小肠匀浆的高速上清液中含有一种热稳定、可透析的因子，该因子对组织盐提取物中的过氧化物酶活性呈现出时间依赖性抑制作用。通过在Dowex 50W-X8上进行色谱分离对该抑制剂进行了纯化，并鉴定为黄嘌呤。黄嘌呤氧化酶的抑制剂别嘌呤醇可阻止黄嘌呤对过氧化物酶的抑制作用，同时发现次黄嘌呤也具有抑制作用。结果表明，黄嘌呤氧化酶催化反应中产生的H2O2是观察到的抑制作用的直接原因。在小肠的NH4Cl提取物中，黄嘌呤或次黄嘌呤存在时过氧化物酶活性随时间的丧失比在CaCl2提取物中更快，这是由于这两种提取物中H2O2的初始浓度不同所致。本文讨论了大鼠小肠中过氧化物酶与黄嘌呤氧化酶之间可能的关系。
