Structural impairment of the renal proximal tubular epithelium induced by cadmium (Cd) was investigated by measuring the concentration of neutral endopeptidase 24.11 (NEP), an ectoenzyme of the apical brush border, in the urine of 106 male workers employed in a Cd smelter (among whom 52 were occupationally exposed to Cd), and by comparing it with other tubular markers flow molecular weight proteins, lysosomal enzymes).
Methods-NEP (EC 184.108.40.206), bêta-N-acetyl-glucosaminidase (NAG) (EC 3.2.1. 30), and NAG-B isoenzyme activities were measured by fluorimetric assays, whereas the concentrations of retinol binding protein (RBP), bêta2-microglobufin (bêta2M), and Clara cell protein (CC16) were measured by automated latex agglutination techniques.
An increased urinary excretion of NEP as well as microproteins was found only in subjects excreting more than 5 mug Cd/g creatinine.
In this group, NEP concentrations were significantly higher in the subjects who smoked.
This significant interaction could not be found for any other marker tested.
Conclusions-The data suggest that NEP enzymuria is high even at low exposures to Cd (with a threshold of urinary cadmium excretion (U-Cd) at 5 mug/g creatinine), indicating early structural alterations.
Moreover, its particular sensitivity to smoking could be useful in the detection of new population clusters potentially more susceptible to development of nephrotoxic insult.
Mots-clés Pascal : Cadmium, Métal lourd, Toxicité, Exposition professionnelle, Médecine travail, Homme, Surveillance biologique, Urine, Liquide biologique, Endopeptidase, Peptidases, Hydrolases, Enzyme, Tabagisme, Tube rénal, Marqueur biologique, Neprilysin, Metalloendopeptidases, Appareil urinaire pathologie
Mots-clés Pascal anglais : Cadmium, Heavy metal, Toxicity, Occupational exposure, Occupational medicine, Human, Biological monitoring, Urine, Biological fluid, Endopeptidase, Peptidases, Hydrolases, Enzyme, Tobacco smoking, Renal tubule, Biological marker, Neprilysin, Metalloendopeptidases, Urinary system disease
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 97-0411736
Code Inist : 002B03L05. Création : 19/12/1997.