- Inhibition of enzymes involved in heme synthesis.
- Binding of lead to transferrin inhibiting the transport of iron.
- Binding of lead to cell membrane of erythroid precursors.
- Binding of lead to ferritin inhibiting their breakdown into hemosiderin.
20110519
The pathogenesis of hypochromic anemia in lead poisoning is due to:
1. Inhibition of enzymes involved in heme synthesis.
ReplyDeleteOne of the main causes for the pathology of lead is that it interferes with the activity of an essential enzyme called delta-aminolevulinic acid dehydratase, or ALAD, which is important in the biosynthesis of heme, the cofactor found in hemoglobin. Lead also inhibits the enzyme ferrochelatase, another enzyme involved in the formation of heme. Ferrochelatase catalyzes the joining of protoporphyrin and Fe2+ to form heme. Lead's interference with heme synthesis results in production of zinc protoporphyrin and the development of anemia. Another effect of lead's interference with heme synthesis is the buildup of heme precursors, such as aminolevulinic acid, which may be directly or indirectly harmful to neurons.