Adaptative increase of ornithine production and decrease of ammonia metabolism in rat colonocytes after hyperproteic diet ingestion.

This would be an interesting explanation at the hypothesis that the failure to adapt leads to environmental illess. Of course, the failure of the Nrf2 antioxidant system to work effectively is also maladaptive...and there has been studies that suggest that Nrf2 may regulate this pathway to some extent. Lowering protein levels may be an additional way to reduce some EI symptoms and deserves much further study!

". In response to increased NH(4)(+)/NH(3) concentration in the colon, the increased capacity of the colonocytes to synthesize l-ornithine is likely to correspond to an elevated l-ornithine requirement for the elimination of excessive blood ammonia in the liver urea cycle"

Read more: CiteULike: Adaptative increase of ornithine production and decrease of ammonia metabolism in rat colonocytes after hyperproteic diet ingestion.:

Central tetrahydrobiopterin concentration in neurodevelopmental disorders.

Hmmm, I would say considering that Nrf2 helps to maintain coupling of NO via tetrahydrobiopterin....the resources of methionine, proper functionings of the pathway and methylation status of the pathways involved may throw a really big wrench into things....and could account for a number of conditions including those in autism and other environmental illnesses including multiple chemical sensitivity or idiopathic intolerance.

"citrulline-to-methionine was found to correlate with the cerebrospinal fluid BH(4) concentration (r = -0.67, p < 0.05). Both citrulline and methionine are substrates in inflammation and oxidative stress pathways - two pathways that utilize BH(4) and are abnormally activated in autism. These data suggests that central BH(4) concentration may be related to systemic inflammation and oxidative stress pathways."

Read more: CiteULike: Central tetrahydrobiopterin concentration in neurodevelopmental disorders.:

Further Reading:

• Dysfunction of Methylation and Nrf2 in Environmental Illness-  
  Is This A Better Explanation than NO/ONOO- ?
  
  

Additional Citation:

• Frye, R. E., Huffman, L. C., and Elliott, G. R. (2010). Tetrahydrobiopterin as a novel therapeutic intervention for autism. Neurotherapeutics : the journal of the American Society for Experimental NeuroTherapeutics, 7(3):241-249.
  http://www.citeulike.org/user/HEIRS/article/7557630