RESUMO
Inhibition of Hb biosynthesis in lead intoxicated subjects appears as a result of disorder in the interaction of Cu, Zn and Fe ions on delta-Am-inolevulinic acid dehydratase. [ALA-D]. Elevation of free serum copper and decrease of serum iron and zinc are the main cause of ALAD inhibition. Thus, it is safe to suggest that administration of Zn orally leads to replacement of cu from catalytic sites of this enzyme which is known as a zinc dependent enzyme
Assuntos
Humanos , Masculino , Zinco/sangue , Cobre/sangue , Ferro/sangue , 5-Aminolevulinato Sintetase , Ácido Aminolevulínico/urina , Sintase do Porfobilinogênio , Chumbo/sangue , Transferrina , Ceruloplasmina , Espectrofotometria AtômicaRESUMO
Changes in the hemoglobin-oxygen dissociation curve and the factors which influence its position were studied in lead poisoned subjects as compared to normal controls. Hemgolobin showed a lower than normal affinity for 02, and this could be considered as a protection against tissue anoxia. It is of interest to notice that 2,3 DPG and plasma inorganic phosphate were elevated with lead poisoning increment