23 Porphyrias
- anything increases activity of P450 can exacerbate condition
- anemia can result with severe inhibition of enzymes
Porphyria
- two common ones are hepatic porphyria: heme synthesis affected in liver
PCT
- some carboxyl groups have 3 carbons, others 2
- A for acetic, P for propionic
- Uroporphyrinogen III must be oxidized, lose H2, to be converted to uroporphyrin III
- skin major symptoms (cutanea)
- heptatitis from uroporphyrins accumulation in liver
- in kidney: tea colored urine
- iron overload like hemochromatosis
- determine high porphyrin, then fractionate to determine high uroporphyrin
- vampire hypothesis
- consume heme/blood, inhibit heme synthesis
Acute Intermittent
- late in pathway: skin symptoms
- early in pathway: neurologic symptoms
- low glucose, increased ALA synthase, rising heme
- confusion, delirium, dementia
- inhibited porphobilinogen deaminase and increased D ala synthase leads to increased D ala and porphobilinogen
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