Possible Interaction: Dopamine and Homocysteine

“This is important because homocysteine prevents blood and other nutrients from reaching the brain, and interferes with the production of serotonin, dopamine , and norepinephrine—all regulators of mood, sleep, and appetite.”

“Unilateral intranigral infusion of Hcy (1.0 μmol in 2 μl) caused inhibition of mitochondrial complex-I activity, decrease in the level of striatal dopamine , loss of midbrain dopaminergic neurons, and motor abnormalities.”

“Animals infused unilaterally with different doses of homocysteine (0.25-1 micromol in 1 microl) intranigrally exhibited significant and dose-dependent decrease in dopamine levels in the ipsilateral striatum as assayed employing an HPLC coupled with electrochemical detector, 19 days post-infusion.”

“The intraperitoneal injections of two doses of homocysteine significantly increased homocysteine levels in the striatal regions of mouse brains by 21.5 and 39.2%, while reducing dopamine turnover rates in the striatal regions by decreasing (DOPAC+HVA)/DA, 23.7 and 51.6%, respectively.”

“… dopamine [minimum effective concentrations (MECs): 3 X 10(-6)-10(-5) M], DL-octopamine (MECs: 2 X …), 5-hydroxytryptamine (MEC: 3 X 10(-6) M), GABA (MEC: 3 X 10(-4) M), L-homocysteic acid (MECs: 3 X 10(-5)-10(-4) … acid (MEC: 3 X 10(-5) M).”

“However, the self-polymerization of DA could be effectively inhibited in the presence of antioxidants including glutathione (GSH), ascorbic acid (AA), cysteine (Cys), and homocysteine (Hcys).”