van Waeg G, Niklasson F, Ericson A, de Verdier C H
Departmet of Clinical Chemistry, Uppsala University, Akademiska Sjukhuset, Sweden.
Clin Chim Acta. 1988 Feb 15;171(2-3):279-92. doi: 10.1016/0009-8981(88)90154-4.
Fresh and stored erythrocytes from normal and ITP-pyrophosphohydrolase (ITP-ase, EC 3.6.1.19) deficient individuals were incubated with hypoxanthine, guanine, allopurinol, and inosine. Differences in the purine metabolism between the normal and the ITP-ase deficient erythrocytes were observed only in the IMP-ITP cycle. Hypoxanthine, guanine and allopurinol were converted to nucleotides at the same rate. Hypoxanthine (2.5 mumol/l) inhibited the salvage of allopurinol (40 mumol/l). A slow decrease (0.7%/day) in salvage rate was observed in both types of cells upon storage at +4 degrees C. Erythrocyte ITP-ase activity was measured in a reference sample group of 48 healthy volunteers. Two distinct groups were found with mean activities equal to 48.3 +/- 13.1 nkat/g Hb (means +/- SD, n = 38) and 11.4 +/- 4.3 nkat/g Hb (n = 10). In two previously selected subjects, the ITP-ase activity was 0.2 and 2.4 nkat/g Hb. A hypothetical genetic mechanism is discussed. The maximal energy turnover in the IMP-ITP cycle during hypoxanthine incubation was found to be less than 10% of the basal erythrocyte energy turnover.
将来自正常个体以及血小板减少性紫癜焦磷酸水解酶（ITP酶，EC 3.6.1.19）缺陷个体的新鲜红细胞和储存红细胞与次黄嘌呤、鸟嘌呤、别嘌呤醇及肌苷一起孵育。仅在肌苷酸-三磷酸肌醇（IMP-ITP）循环中观察到正常红细胞和ITP酶缺陷红细胞之间嘌呤代谢的差异。次黄嘌呤、鸟嘌呤和别嘌呤醇以相同的速率转化为核苷酸。次黄嘌呤（2.5 μmol/L）抑制别嘌呤醇（40 μmol/L）的补救合成。在4℃储存时，两种类型的细胞均观察到补救合成率缓慢下降（0.7%/天）。在48名健康志愿者的参考样本组中测定了红细胞ITP酶活性。发现两个不同的组，其平均活性分别为48.3±13.1 nkat/g血红蛋白（平均值±标准差，n = 38）和11.4±4.3 nkat/g血红蛋白（n = 10）。在两个先前选定的受试者中，ITP酶活性分别为0.2和2.4 nkat/g血红蛋白。讨论了一种假设的遗传机制。发现在次黄嘌呤孵育期间IMP-ITP循环中的最大能量周转率低于基础红细胞能量周转率的10%。
