L-Tyrosine D4 is a deuterium labeled L-Tyrosine. L-Tyrosine is a non-essential amino acid which can inhibit citrate synthase activity in the posterior cortex[1].
L-Tyrosine inhibits citrate synthase activity in the posterior cortex (2.0 and 4.0 mM), malate dehydrogenase is not altered by L-Tyrosine and succinate dehydrogenase is increased in the posterior cortex (0.1-4.0 mM), hippocampus (1.0-4.0 mM), striatum (4.0 mM) and liver (0.1-4.0 mM)[1].
[1]. Ferreira GK, et al. Effect of L-tyrosine in vitro and in vivo on energy metabolism parameters in brain and liver of young rats. Neurotox Res. 2013 May;23(4):327-35.