THE INVERSE RELATIONSHIP BETWEEN THE ACTIVITY OF PYRIDOXAL KINASE AND THE LEVEL OF BIOGENIC AMINES IN RABBIT BRAIN¹

Abstract

Abstract— In a series of experiments, an inverse relationship was found to exist between the activity of pyridoxal kinase and the concentrations of brain norepinephrine, dopamine, and serotonin. When the biogenic amine content of the brain is lowered, the activity of pyridoxal kinase rises. Conversely, when the concentration of brain biogenic amines is elevated, a depression occurs in the activity of pyridoxal phosphokinase. This relationship, which resembles an in vivo allosteric inhibition phenomenon, not only is highly suggestive of a definite relation between the brain vitamin B 6 content and the metabolism of the biogenic amines, but also suggests that the concentration of brain biogenic amines might control the production of coenzyme pyridoxal phosphate.