Santos J L, Fontanellas A, Batlle A M, Enríquez de Salamanca R E
Porphyria Unit, Hospital Universitario Doce de Octubre, Madrid, Spain.
Ecotoxicol Environ Saf. 1998 Mar;39(3):168-71. doi: 10.1006/eesa.1997.1613.
5-Aminolevulinate dehydrase (ALA-D) and porphobilinogen deaminase (PBG-D) are cytosolic enzymes involved in heme biosynthesis. ALA-D activity is altered both genetically and by the action of various environmental factors, including exposure to lead. The activity of PBG-D is reduced in acute intermittent porphyria. The aim of this work is to establish the 95% reference range of the erythrocytic activity of ALA-D and PBG-D in a control population. ALA-D activity limits were 15.8 and 50.2 nmol of PBG/ml of red blood cells (RBCS) per minute. For the activity of ALA-D restored by addition of zinc and dithiothreitol ("restored ALA-D"), these limits were 44.1 and 86.5 units. It has been found that the "restored ALA-D"/ALA-D ratio is very useful for the evaluation of lead toxicity, and its 95% reference range was between 1.22 and 3.06. It has been demonstrated that the best method for measuring erythrocytic PBG-D is using PBG, but not ALA, as substrate; its 95% reference range was between 20.9 and 63.2 nmol of uroporphyrin/ml of RBCs per hour. Knowledge of these reference range values in a control population constitutes the basis for an accurate diagnosis of heavy metal intoxication and acute intermittent porphyria.
5-氨基酮戊酸脱水酶（ALA-D）和胆色素原脱氨酶（PBG-D）是参与血红素生物合成的胞质酶。ALA-D的活性在遗传上以及受包括铅暴露在内的各种环境因素的作用而发生改变。在急性间歇性卟啉症中，PBG-D的活性降低。这项工作的目的是确定对照组人群中红细胞ALA-D和PBG-D活性的95%参考范围。ALA-D活性的限度为每分钟每毫升红细胞（RBC）中15.8至50.2纳摩尔的PBG。对于通过添加锌和二硫苏糖醇恢复的ALA-D活性（“恢复的ALA-D”），这些限度为44.1至86.5单位。已发现“恢复的ALA-D”/ALA-D比值对于评估铅毒性非常有用，其95%参考范围在1.22至3.06之间。已证明测量红细胞PBG-D的最佳方法是使用PBG而非ALA作为底物；其95%参考范围为每小时每毫升RBC中20.9至63.2纳摩尔的尿卟啉。了解对照组人群中的这些参考范围值是准确诊断重金属中毒和急性间歇性卟啉症的基础。
