The pathogenesis of hypochromic anemia in lead poisoning is due to -
Iron should be combined with protoporphyrin to synthesize Heme. To synthesize protoporphyrin and combine it with iron, enzymes like ALA synthase, ALA dehydratase & Ferrochelatase are required. Lead inhibits heme synthesis by inhibiting enzymes ALA dehydratase & Ferrochelatase resulting in microcytic hypochromic anemia.
Lead blocks transferrin receptors of erythroid precursors
Binding of lead to transferrin, inhibiting the transpo of iron
Inhibition of enzymes involved in heme biosynthesis
Inhibiting breakdown of ferritin into hemosiderin
Iron deficiency anemia