Elevated Levels of Ammonia Impair the NO/cGMP Through Alterations of Cellular Transporters~!

In other blogs, I have suggested that alterations in the NO/cGMP pathway by environmental factors may influence environmental disease including CFS and MCS. Several recent studies have suggested a relationship between the NO/cGMP pathway and the activation of the Nrf2. Because the Nrf2 has a neuroprotective role on astrocytes and neurons, the failure of this pathway could contribute to neurological damage commonly associated with aging as well as, other neurological disorders. In this most recent study, the author provides more evidence that in cases of hyperammonemia, the No/cGMP pathway activity is decreased and therefore, may provide some explanation for damage resulting from high ammonia levels.

"reduced delivery of Arg due to enhanced y(+)LAT2-mediated exchange of extracellular Gln for intracellular Arg may contribute to the decrease of NO/cGMP pathway activity evoked in the brain by HA."

Zielińska, M., Ruszkiewicz, J., Hilgier, W., Fręśko, I., and Albrecht, J. (2010). Hyperammonemia increases the expression and activity of the glutamine/arginine transporter y(+)LAT2 in rat cerebral cortex: implications for the nitric oxide/cGMP pathway. Neurochemistry international. http://www.citeulike.org/user/HEIRS/article/8341074
Sidoryk-Wegrzynowicz, M., Wegrzynowicz, M., Lee, E., Bowman, A., and Aschner, M. (2010). Role of Astrocytes in Brain Function and Disease. Toxicologic pathology.  http://www.citeulike.org/user/HEIRS/article/8341171