Homocysteine impairs coronary artery endothelial function by inhibiting tetrahydrobiopterin in patients with hyperhomocysteinemia.

Hmm...seems like this is right in line with why some therapies for MCS and autism.  Note: Nrf2 is involved with maintaining coupling of NO and BH4.

Homocysteine impairs coronary artery endothelial function by inhibiting tetrahydrobiopterin in patients with hyperhomocysteinemia.

Active nf-e2-related factor (nrf2) contributes to keep endothelial no synthase (enos) in the coupled state: role of reactive oxygen species (ros), enos, and heme oxygenase (ho-1) levels.

Heiss, E. H., Schachner, D., Werner, E. R., and Dirsch, V. M. (2009). Active nf-e2-related factor (nrf2) contributes to keep endothelial no synthase (enos) in the coupled state: role of reactive oxygen species (ros), enos, and heme oxygenase (ho-1) levels. The Journal of biological chemistry, 284(46):31579-31586. http://www.citeulike.org/user/HEIRS/article/5886348

Glutathione depletion in nigrostriatal slice cultures: Gaba loss, dopamine resistance and protection by the tetrahydrobiopterin precursor sepiapterin

Gramsbergen, J. B. B., Sandberg, M., Møller Dall, A., Kornblit, B., and Zimmer, J. (2002). Glutathione depletion in nigrostriatal slice cultures: Gaba loss, dopamine resistance and protection by the tetrahydrobiopterin precursor sepiapterin. Brain research, 935(1-2):47-58. http://www.citeulike.org/user/HEIRS/article/6307660