HEREDITARY XANTHINURIA - EVIDENCE FOR ENHANCED HYPOXANTHINE SALVAGE
HEREDITARY XANTHINURIA - EVIDENCE FOR ENHANCED HYPOXANTHINE SALVAGE
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DOI：
10.1172/jci112893
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发表时间：
1987-03-01
影响因子：
15.9
通讯作者：
FOX, IH
中科院分区：
文献类型：
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作者：
MATEOS, FA;PUIG, JG;FOX, IH
我们测试了两个患有遗传性黄嘌呤尿症的兄弟姐妹的次黄嘌呤挽救率较高的假设。我们用[8-14C]腺嘌呤对腺嘌呤核苷酸库进行放射性标记，并检查静脉注射果糖后嘌呤核苷酸的降解情况。 5天期间放射性的累积排泄分别为酶缺乏患者输注放射性的9.7%和9.1%以及6.0.+-。四名正常受试者中为 0.7%（平均值.+-.SE）。果糖输注使尿放射性增加至7.96和9.16倍。两名患者的肌酐均为 106 cpm/g，并达到 4.73 .+-。 0.69倍对照组肌酐为 106 cpm/g。输注果糖使患者的总尿嘌呤排泄量从正常低基线值增加到平均 487%，并增加到 398.+-。对照组为 86%。在酶缺乏的患者中，果糖的输注引起血浆鸟苷从不可检测的值增加至0.7和0.9μM。通过对肠道嘌呤损失进行调整，这些数据支持这样的假设：遗传性黄嘌呤尿症中次黄嘌呤的补救率有所提高。鸟嘌呤核苷酸降解为黄嘌呤绕过了次黄嘌呤补救途径，并且可以解释这种尿嘌呤化合物在黄嘌呤尿症中的主导地位。
We tested the hypothesis that there is an enhanced rate of hypoxanthine salvage in two siblings with hereditary xanthinuria. We radiolabelled the adenine nucleotide pool with [8-14C]adenine and examined purine nucleotide degradation after intravenous fructose. The cumulative excretion of radioactivity during a 5-d period was 9.7% and 9.1% of infused radioactivity in the enzyme-deficient patients and 6.0 .+-. 0.7% (mean .+-. SE) in four normal subjects. Fructose infusion increased urinary radioactivity to 7.96 and 9.16 .times. 106 cpm/g creatinine in both patients and to 4.73 .+-. 0.69 .times. 106 cpm/g creatinine in controls. The infusion of fructose increased total urinary purine excretion to a mean of 487% from low-normal baseline values in the patients and to 398 .+-. 86% in control subjects. In the enzymne-deficient patients, the infusion of fructose elicited an increase of plasma guanosine from undetectable values to 0.7 and 0.9 .mu.M. With adjustments made for intestinal purine loss, these data support the hypothesis that there is enhanced hypoxanthine salvage in hereditary xanthinuria. Degradation of guanine nucleotides to xanthine bypasses the hypoxanthine salvage pathway and may explain the predominance of this urinary purine compound in xanthinuria.