Urinary porphyrins and heme biosynthetic enzyme activities measured by HPLC in arsenic toxicity.

Arsenic can modify the urinary excretion of porphyrins in animals and humans. Arsenic also interferes with the activities of several enzymes of the heme biosynthesis pathway, such as aminolevulinate synthase (ALA-S), porphobilinogen deaminase (PBGD), uroporphyrinogen III synthase (Uro III S), uroporphyrinogen decarboxylase (URO-D), coproporphyrinogen oxidase (COPRO-O), ferrochelatase and heme oxygenase (H-O). This review deals with HPLC-based techniques for the analysis of porphyrins in human and rodent urine and several heme enzymes with discussion on their usefulness as early biomarkers of arsenic toxicity.