Our objective was to evaluate the activities of some enzymes of the heme biosynthesis pathway and their relationship with the profile of urinary porphyrin excretion in individuals exposed chronically to arsenic (As) via drinking water in Region Lagunera, Mexico.
We selected 17 individuals from each village studied : Benito Juarez, which has current exposure to 0.3 mg As/I ; Santa Ana, where individuals have been exposed for more than 35 years to 0.4 mg As/l, but due to changes in the water supply (in 1992) exposure was reduced to its current level (0.1 mg As/l), and Nazareno, with 0.014 mg As/l. Average arsenic concentrations in urine were 2058,398, and 88 mug As/g creatinine, respectively.
The more evident alterations in heme metabolism observed in the highly exposed individuals were :
(1) small but significant increases in porphobilinogen deaminase (PBG-D) and uroporphyrinogen decarboxylase (URO-D) activities in peripheral blood erythrocytes ;
(2) increases in the urinary excretion of total porphyrins, mainly due to coproporphyrin III (COPROIII) and uroporphyrin III (UROIII) ;
and (3) increases in the COPRO/URO and COPROIII/COPROI ratios.
No significant changes were observed in uroporphyrinogen III synthetase (UROIII-S) activity. (...)
Mots-clés Pascal : Arsenic, Santé et environnement, Toxicité, Pollution eau, Eau potable, Dose répétée, Mexique, Amérique Centrale, Amérique, Homme, Evaluation, Activité enzymatique, Enzyme, Hème, Biosynthèse, Porphyrine, Uroporphyrinogen decarboxylase, Carboxy-lyases, Carbon-carbon lyases, Lyases
Mots-clés Pascal anglais : Arsenic, Health and environment, Toxicity, Water pollution, Drinking water, Multiple dose, Mexico, Central America, America, Human, Evaluation, Enzymatic activity, Enzyme, Heme, Biosynthesis, Porphyrin, Uroporphyrinogen decarboxylase, Carboxy-lyases, Carbon-carbon lyases, Lyases
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 99-0260095
Code Inist : 002B03L05. Création : 16/11/1999.