title: Reference values of 5-aminolevulinate dehydrase and porphobilinogen deaminase in the Spanish population from Madrid.
abstract: 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.
authors.affiliation: Porphyria Unit, Hospital Universitario Doce de Octubre, Madrid, Spain.
authors.forename: J L
authors.initials: JL
authors.lastname: Santos
authors.forename: A
authors.initials: A
authors.lastname: Fontanellas
authors.forename: A M
authors.initials: AM
authors.lastname: Batlle
authors.forename: R E
authors.initials: RE
authors.lastname: Enríquez de Salamanca
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004912:Erythrocytes / Q000187:drug effects / Q000201:enzymology*; D005260:Female; D006801:Humans; D011163:Hydroxymethylbilane Synthase / Q000097:blood*; D008297:Male; D008875:Middle Aged; D000623:Porphobilinogen Synthase / Q000097:blood*; D011164:Porphyrias / Q000097:blood / Q000175:diagnosis; D012016:Reference Values; D013030:Spain; D014505:Urban Population; D014578:Uroporphyrins / Q000097:blood; D015032:Zinc / Q000494:pharmacology
chemical_list: D014578:Uroporphyrins; D011163:Hydroxymethylbilane Synthase; D000623:Porphobilinogen Synthase; D015032:Zinc