de Jong J W, van der Meer P, Nieukoop A S, Huizer T, Stroeve R J, Bos E
Thoraxcenter, Erasmus University Rotterdam, Netherlands.
Circ Res. 1990 Sep;67(3):770-3. doi: 10.1161/01.res.67.3.770.
Oxygen free radicals generated by xanthine oxidase have been implicated in cardiac damage. The activity of xanthine oxidase/reductase in adult rat heart is considerable. Its assay gives controversial results for other species, for example, rabbits and humans. Therefore, we perfused isolated hearts of various species, including explanted human hearts, to measure the conversion of exogenous hypoxanthine to xanthine and urate. We assayed these purines with high-performance liquid chromatography. The apparent xanthine oxidoreductase activities, calculated as release of xanthine plus 2x urate, were (milliunits per gram wet weight, mean +/- SEM) mice 33 +/- 3 (n = 5), rats 28.5 +/- 1.4 (n = 9), guinea pigs 14.4 +/- 1.0 (n = 5), rabbits 0.59 +/- 0.09 (n = 5), pigs less than 0.1 (n = 6), humans 0.31 +/- 0.04 (n = 7), and cows 3.7 +/- 0.8 (n = 4). In rabbit heart the conversion of hypoxanthine to xanthine was slow, and that of xanthine to urate was even slower. On the other hand, guinea pig and human heart released little xanthine, indicating that xanthine breakdown exceeds its formation. We conclude that isolated perfused mouse, rat, guinea pig, and also bovine hearts show considerable xanthine oxidoreductase activity, contrasting rabbit, porcine, and diseased human hearts.
黄嘌呤氧化酶产生的氧自由基与心脏损伤有关。成年大鼠心脏中黄嘌呤氧化酶/还原酶的活性相当高。对于其他物种，如兔子和人类，其活性测定结果存在争议。因此，我们灌注了包括人离体心脏在内的各种物种的离体心脏，以测量外源性次黄嘌呤向黄嘌呤和尿酸盐的转化。我们用高效液相色谱法测定这些嘌呤。以黄嘌呤加2倍尿酸盐的释放量计算的表观黄嘌呤氧化还原酶活性（每克湿重毫单位，平均值±标准误）为：小鼠33±3（n = 5），大鼠28.5±1.4（n = 9），豚鼠14.4±1.0（n = 5），兔子0.59±0.09（n = 5）,猪小于0.1（n = 6），人类0.31±0.04（n = 7），牛3.7±0.8（n = 4）。在兔心脏中，次黄嘌呤向黄嘌呤的转化缓慢，而黄嘌呤向尿酸盐的转化甚至更慢。另一方面，豚鼠和人心脏释放的黄嘌呤很少，表明黄嘌呤的分解超过其形成。我们得出结论，离体灌注的小鼠、大鼠、豚鼠以及牛心脏显示出相当高的黄嘌呤氧化还原酶活性，这与兔、猪和患病人类心脏形成对比。
