Postulated mechanism whereby uroporphrinogen is oxidized to uroporphyrin

Postulated mechanism for UROD inhibition in porphyria cutanea tarda. Uroporphrinogen is oxidized by cytochrome P450 enzymes (especially CYP1A2) in the presence of iron to uroporphomethene, a specific UROD inhibitor, and uroporphyrin, which accumulates in the liver.