Premium
THE EFFECT OF l ‐DOPA AND AN INHIBITOR OF PERIPHERAL DECARBOXYLATION ON GLUCOSE METABOLISM IN BRAIN 1
Author(s) -
Tyce Gertrude M.
Publication year - 1976
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1976.tb02621.x
Subject(s) - aromatic l amino acid decarboxylase , chemistry , tyrosine , decarboxylation , tryptophan , phenylalanine , decarboxylase inhibitor , metabolism , amino acid , arginine , biochemistry , aromatic amino acids , endocrinology , medicine , enzyme , biology , levodopa , disease , parkinson's disease , catalysis
– The effect of the administration of l ‐DOPA plus an inhibitor of peripheral l ‐aromatic amino acid decarboxylase (aromatic‐ l ‐amino‐acid carboxy‐lyase; EC 4.1.1.28) on the metabolism of glucose in brain was studied by administering [U‐ I4 C]glucose (20μCi) to three groups of rats: (1) rats that had been injected with l ‐DOPA (200mg/kg) 28min earlier; (2) rats that had been similarly injected with l ‐DOPA and also with N ‐( d,l ‐seryl)‐ N ′‐(2,3,4‐trihydroxybenzyl)hydrazine (50 mg/kg), an inhibitor of l ‐aromatic amino acid decarboxylase, 30min before the l ‐DOPA; and (3) appropriate controls. The flux of 14 C from glucose in plasma to those amino acids that are in equilibrium with the tricarboxylic acid cycle intermediates was reduced by treatment with l ‐DOPA and reduced further by treatment with l ‐DOPA and the decarboxylase inhibitor. Concentrations of glucose in brain and in plasma were increased after treatment with l ‐DOPA; these increases were attenuated if the inhibitor was given before the l ‐DOPA. After treatment with l ‐DOPA, there were decreases in the concentration of aspartate, tryptophan, and tyrosine in brain. After the administration of l ‐DOPA and the decarboxylase inhibitor, the concentrations in brain of alanine, glutamate, tyrosine, and phenylalanine were greater, and the concentrations of aspartate, leucine, lysine, histidine, arginine, and tryptophan were less than in control rats.