NEUR 3502 Lecture Notes - Lecture 15: Phenylalanine, Essential Amino Acid, Phenylketonuria

• School: Carleton University
• Department: Neuroscience
• Course: NEUR 3502
• Professor: Patrice Smith

Document Summary

Then this can propose an issue: phenylalanine metabolism in absence of pah. Without pah, phenylalanine is metabolized into phenylpyruvic acid by transaminase: resulting in a build-up of phenylpyruvic acid that could cause neuronal death. There is another mechanism that allows for phenylpyruvic acid (considered to be toxic) Tyrosine produces dopamine (neurotransmitter), so if there isn"t a significant amount of. Pah then it will result in the loss of production. In the absence of pah, you end up with the accumulation of the potentially toxic substances which can potentially inhibit myelinating processes. Lots of consequences regarding the dysregulation of serotnergi levels in the brain: dopamine reduction hypothesis, phenylalanine not converted to tyrosine in absence of pah. Less tyrosine produced: tyrosine needed to produce dopamine in the brain, resulting in reduced da levels in the brain, reduced dopamine levels in the cerebral spinal fluid of pku patients, prefrontal cortex sensitive to reduction in dopamine levels.