The following laboratory results are associated with which toxic trace element?
Delta-aminolevulinic acid - increased
Free erythrocyte protoporphyrin (zinc protoporphyrin) - increased
Anemia screen - positive

Question

Quizplus · Accepted Answer

Lead inhibits two enzymes in the porphyrin synthetic pathway.The first enzyme inhibited is delta-aminolevulinic acid dehydratase.Inhibition of this enzyme results in an increased delta-aminolevulinic acid.The second enzyme inhibited by lead is ferrochelatase.Inhibition of this enzyme prevents the insertion of iron into protoporphyrin, leaving protoporphyrin free to combine with zinc.Thus lead is associated with an increased zinc protoporphyrin.As blood lead levels reach approximately 40 μg/L, anemia usually becomes evident.

The Following Laboratory Results Are Associated with Which Toxic Trace