USMLE Starvation and Acute Intermittent Phorphyria?

[Fallot101]

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Hi guys,

So I get the deal about how P450 inducers may precipitate Acute Intermittent Porphyria (via ↓ heme and induction of ALA synthase). But what's the deal with starvation (mentioned by FA, pg395)?

 

[KnockKnock]

I believe starvation activates heme synthesis, which would then exacerbate AIP.

This article discusses the effects of starvation in E. coli as up-regulating the 5-ALA synthesis step:
https://www.ncbi.nlm.nih.gov/pubmed/9267433

 

[Fallot101]

So I found this: http://www.cell.com/cell/fulltext/S0092-8674(05)00813-5.

 

[Shams al Deen]

I just remembered it by the fact that glucose inhibits ALA synthase. Makes sense that starvation (low glucose) would turn that pathway on, increasing buildup of porphobilinogen and d-ALA