Environmental lead exposure and activity of delta-aminolevulinic acid dehydratase (ALA-D) in maternal and cord blood.
The hypothesis that environmental lead exposure measured from blood (Pb-B) inhibits delta-aminolevulinic acid dehydratase activity (ALA-D) from whole blood was tested in 241 urban mothers and their newborns. Geometric means and (5th and 95th Percentiles) for maternal and cord Pb-B were 6.4 microg dl(-1) (3.4-11.9) and 4.6 microg dl(-1) (2.8-9.2). Spearman correlations between mother and cord Pb-B and ALA-D were all negative but statistically significant only for cord Pb-B and mother ALA-D. A potential lead threshold, was identified between 3.2 and 4.8 microg dl(-1), above which ALA-D may be inhibited by lead, and below which ALA-D may be insensitive or even activated. In conclusion, low environmental exposure to lead is responsible for a demonstrable biochemical effect. This potential ALA-D inhibition may lead to neurotoxic effects, especially in newborns who have high level of neurogenesis.
French National Institute of Health and Medical Research (INSERM, U-472), Epidemiology and Biostatistic Research Unit, Villejuif.
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Campagna
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Huel
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Girard
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Sahuquillo
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D000328:Adult; D005260:Female; D005312:Fetal Blood / Q000201:enzymology*; D006801:Humans; D007231:Infant, Newborn; D007854:Lead / Q000097:blood; D007855:Lead Poisoning / Q000201:enzymology*; D000623:Porphobilinogen Synthase / Q000037:antagonists & inhibitors* / Q000097:blood; D011247:Pregnancy; D011248:Pregnancy Complications / Q000201:enzymology*
D007854:Lead; D000623:Porphobilinogen Synthase