In order to assess whether lead in bone is available for chelation by 2,3 meso-dimercaptosuccinic acid (DMSA), 21 workers (10 active and 11 retired) from a secondary lead smeltery were studied.
A morning urine sample was obtained from all participants, followed by ingestion of 10 mg per kg body weight of the chelating agent DMSA.
All urine produced during the following 24h was collected in consecutive 6-and 18-h portions.
Concentrations of lead in blood (B-Pb) and urine were determined by flameless atomic absorption spectrometry (AAS), in plasma (P-Pb) by inductively coupled plasma mass spectrometry (ICP-MS), and in finger bone (Bone-Pb) by K X-ray fluorescence technique (XRF).
DMSA-chelatable lead excreted in the 24-h portion correlated well with the excretion in the 6-h portion (U-Pb6h ; rs=0.95 ; P<0.001).
U-Pb6h showed a non-linear relationship to B-Pb (rs=0.84 ; P<0.001) and linear relationships to P-Pb (rs=0.91 ; P<0.001) and lead in morning urine (rs=0.95 ; P<0.001).
In active workers, but not in retired ones, P-Pb and U-Pb6h showed some relationship to Bone-Pb.
In alternative multiple regression models B-Pb or P-Pb were both significant predictors of U-Pb6h, while Bone-Pb did not significantly improve the models.
It can, thus, be concluded that DMSA-chelatable lead mainly reflects lead concentrations in blood, soft tissues, and possibly also trabecular bone.
It is not a good index of total body burden and long-term exposure. (...)
Mots-clés Pascal : Plomb, Porphobilinogen synthase, Hydro-lyases, Carbon-oxygen lyases, Lyases, Enzyme, Comparaison interindividuelle, Métal lourd, Os, Succimer, Toxicité, Antidote, Ostéopathie, Exposition professionnelle, Médecine travail, Chélation, Chélateur, Détection, Taux, Liquide biologique, Sang, Urine, Homme, Corrélation, Relation temps réponse, Génotype, Système ostéoarticulaire pathologie
Mots-clés Pascal anglais : Lead, Porphobilinogen synthase, Hydro-lyases, Carbon-oxygen lyases, Lyases, Enzyme, Interindividual comparison, Heavy metal, Bone, Succimer, Toxicity, Antidote, Bone disease, Occupational exposure, Occupational medicine, Chelation, Chelating agent, Detection, Rate, Biological fluid, Blood, Urine, Human, Correlation, Time response relation, Genotype, Diseases of the osteoarticular system
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 99-0269929
Code Inist : 002B03L05. Création : 16/11/1999.