In lead poisoning, there is an inhibition of some of the enzymes of the heme biosynthetic pathway. This is reflected by the accumulation of what substance in blood?
(A) Uroporphyrinogen III (B) Ferrochelatase (C) Porphob I inogen (D) Delta amino levulinic acid
(D) Ans: D. Delta amino levulinic acid(Ref: Harper 30/e n329)Lead poisoning:Affect heme metabolism by combining with SH groups in ferrochelatase & ALA (delta-amino levulinic acid) dehydratase enzymes.Elevated protoporphyrin levels - Found in RBC's.Elevated ALA & coproporphyrin levels - Found in urine.