Tyrosine

[Stephan Schwartz <schwaste@xxxxxxxxxxxxxxxxxxxxxxx>]

>>> Forrest's Mom <CARLTONL@xxxxxxxxxxx> 06/04/97
04:37am >>>
>>>Nicotinic cholinergic regulation of tyrosine hydroxylase
gene expression and catecholamine synthesis in isolated
bovine adrenal chromaffin cells.
Craviso, GL; Hemelt, VB and Waymire, JC
J Neurochem. 59: 2285-96 (1992)<<<
<<<Generation of Reactive Oxygen Species by Tyrosine
Hydroxylase: A Possible Contribution to the Degeneration of
Dopaminergic Neurons?
Jan Haavik, Dept. of Biochemistry, Univ of Bergen, Norway
6/4/97 4:24 am>>>
<<<Scientific American, June 97. Gene Therapy
6/4/97 12:59 am>>>

Linda -
   Your three posts of 6/4/97 re: tyrosine suggest that adding
the enzyme tyrosine hydroxylase (TH) to a patient's
medication could create larger amounts of dopamine in the
brain.
   TH is a catalyst which promotes a chemical change in the
amino acid, Tyrosine [C9-H11-NO3].  Tyrosine is found in
high protein foods such as fish, nuts and meat.  Tyrosine
helps the transformation to L-Dopa which changes into
dopamine.
   However, whether this chemical reaction is taking place in
the adrenal gland (leading to adrenaline) or in the brain where
the reaction creates dopamine, the biosynthesis is
rate-limited by the enzyme TH.  Hence, the ingestion of large
quantities of protein in a person's diet does not usually lead
to the production of adrenaline.
   Since L-Dopa (an amino acid) is not rate-limited, the
treatment of giving patients L-Dopa (levodopa) was devised
as a way to increase the amount of dopamine formed in the
brain.

Stephan  52/6