Immunological and enzymatic studies of erythrocytic delta-aminolevulinate dehydratase. Comparison of results obtained in normal and lead-exposed subjects.
The delta-aminolevulinate dehydratase (ALA.D) quantitative assay on a centrifugal fast analyser showed that subjects whose blood-lead level varies between 30 and 75 micrograms/100 ml (1.5 to 3.75 microM/l) react to blood intoxication by synthesizing de novo an amount of enzyme correlating to blood-lead levels. At higher concentrations, the reactional synthesis occurs very rarely. These results suggest that enzyme is constitutive, but also inductible as soon as its substrate accumulates; this last ability may disappear at high blood-lead levels: a hypothesis is proposed thereafter.
D000328:Adult; D004229:Dithiothreitol / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D004912:Erythrocytes / Q000201:enzymology*; D006358:Hot Temperature; D006801:Humans; D007854:Lead / Q000097:blood*; D008297:Male; D008875:Middle Aged; D000623:Porphobilinogen Synthase / Q000096:biosynthesis / Q000378:metabolism*; D011524:Protoporphyrins / Q000097:blood; D013053:Spectrophotometry
D011524:Protoporphyrins; C017803:zinc protoporphyrin; D007854:Lead; D000623:Porphobilinogen Synthase; D004229:Dithiothreitol