Excitotoxics (long) and Neuroendocrine Damage

banschbach at vms.ocom.okstate.edu banschbach at vms.ocom.okstate.edu
Fri Aug 20 16:35:24 EST 1993

In article <CBLu7K.792 at dartvax.dartmouth.edu>, James.F.X.Wellehan at dartmouth.edu (Jim Wellehan) writes:
> In article <CBKJ91.2r9 at cunews.carleton.ca>
> wcsbeau at superior.carleton.ca (OPIRG) writes:
>> >>... aspartic acid, glutamic acid or  phenyalanine  blood  spikes
>> >>which  then cause an imbalance in brain neurotransmitters levels
>> >>are similiar to those  that  occur  in  adults.   Dizzyness  and
>> >>headaches  after consuming  food or beverages that contain high
>> >>amounts of these amino acids.
>> Both Glu and Asp have neurotransmitter functions in the mammalian
>> brain.  But I hadn't heard that phenylalanine is now considered a
>> putative neurotransmitter. Could you elaborate on this? (I rather
>> doubt it could be, given that anyone with PKU would automatically
>> be missing a neurotransmitter. Which seems *highly* unlikely.
> I don't know whether F is a neurotransmitter or not, but your last
> comment doesn't make sense.  F is an essential amino acid.  From what I
> understand, people with PKU can't metabolize F and it builds up to
> toxic levels.  This doesn't mean low levels aren't necessary, and I
> doubt it could be completely eliminated.  Please correct me if I'm
> wrong.
> Jim

Phenylalanine is an essential amino acid.  The PKU diet has some 
phenylalanine in it since phenylalanine can not be completely eliminated 
from the human diet.  If your diet has enough phenylalanine, you will not 
need any tyrosine since most of the phenylalanine in your diet is converted 
to tyrosine in the liver using phenylalanine hydroxylase (the enzyme that 
does not work at all in patients with PKU).  The PKU diet has a lot more 
tyrosine in it than phenylalanine.  It's an artifical meat diet since most 
high protein foods contain more phenylalanine than tyrosine.  Once the human 
brain has fully matured at about the age of 9, kids with PKU are switched over
to normal diets but they still have to watch their phenylalanine intake and are 
warned not to consume food or beverages with Nutrasweet.
Marty B.                   "You are what you eat"

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